Ibn Hazm said:

“The jinn are real, and they are creatures created by Allaah. Among them are kaafirs and believers. They can see us but we cannot see them. They eat, have children and die. Allaah says (interpretation of the meanings):

‘O you assembly of jinn and Mankind!’ [al-An’aam 6:130]

‘And the jinn, We created aforetime from the smokeless flame of fire’ [al-Hijr 15:27]

‘And of us some are Muslims (who have submitted to Allaah, after listening to this Qur’aan), and of us some are Al‑Qaasitoon (disbelievers those who have deviated from the Right Path)’. And whosoever has embraced Islam (i.e. has become a Muslim by submitting to Allaah), then such have sought the Right Path.

And as for the Qaasitoon (disbelievers who deviated from the Right Path), they shall be firewood for Hell”’[al-Jinn 72:14-15]

‘Verily, he and Qabeeluhu (his soldiers from the jinn or his tribe) see you from where you cannot see them’[al-A’raaf 7:27]

‘Will you then take him (Iblees) and his offspring as protectors and helpers rat

her than Me’[al-Kahf 18:50]

‘Whatsoever is on it (the earth) will perish’[al-Rahmaan 55:26]

‘Everyone shall taste death’[Aal ‘Imraan 3:185].”

(al-Muhallaa, 1/34/35)

Hence what the questioner has seen may be just her imagination or an illusion, or it may be jinn appearing in a form other than that with which Allaah has created them.

Secondly:

With regard to the jinn harming humans, this is proven to happen and it does happen. Protection against that

is attained by reciting Qur’aan and adhkaar (dhikr) prescribed in sharee’ah.

Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said:

“Undoubtedly the jinn can have a harmful effect on humans, and they could even kill them. They may harm a person by throwing stones at him, or by trying to terrify him, and other things that are proven in the Sunnah or indicated by real events. It was reported that the Messenger (peace and blessings of Allaah be upon him) gave permission to one of his Companions to go to his wife during one of the military campaigns – I think it was the campaign of al-Khandaq – as he was a young man who had recently got married. When he reached his house, he found his wife standing at the door, and he objected to that. She said to him, ‘Go inside,’ so he went inside and found a snake curled up on the bed. He had a spear with him, so he stabbed it with the spear until it died, and at the same instant as the snake died the man also died. It was not known which of them died first, the snake or the man. When the Prophet (peace and blessings of Allaah be upon him) heard of that, he forbade killing the harmless kinds of snakes that are found in houses, apart from those which are maimed or are streaked and malignant.

This indicates that the jinn may attack humans, and that they may harm them, as is known from real-life events. There are numerous reports which indicate that a man may come to a deserted area, and a stone may be thrown at him, but he does not see anybody, or he may hear voices or a rustling sound like the rustling of trees, and other things that may make him feel distressed and scared. A jinn may also enter the body of a human, either because of love or with the intention of harming him, or for some other reason. This is indicated in the aayah (interpretation of the meaning):

‘Those who eat Ribaa will not stand (on the Day of Resurrection) except like the standing of a person beaten by Shaytaan (Satan) leading him to insanity’[al-Baqarah 2:275]

In such cases, the jinn may speak from inside of that person and address the one who is reading verses from the Qur’aan over him; the reciter may take a promise from the jinn never to come back, and other things concerning which there are very many reports which are widespread among the people.

So the protection which will prevent the evil of the jinn is for a person to recite that which is narrated in the Sunnah as being effective in providing protection, such as Aayat al-Kurisy, for if a person recites Aayat al-Kursiy at night, he will continue to have protection from Allaah, and no shaytaan will come near him until morning. And Allaah is the Protector.’”

(Majmoo’ Fataawa al-Shaykh Ibn ‘Uthaymeen, 1/287-288)

The Sunnah mentions adhkhaar (dhikr) by means of which one may gain protection from the shayaateen (devils). These include:

1) Seeking refuge with Allaah from the jinn:

Allaah says (interpretation of the meaning):

“And if an evil whisper from Shaytaan (Satan) tries to turn you away (O Muhammad) (from doing good), then seek refuge in Allaah. Verily, He is the All Hearer, the All Knower”[Fussilat 41:36]

“And if an evil whisper comes to you from Shaytaan (Satan), then seek refuge with Allaah. Verily, He is All-Hearer, All-Knower” [al-A’raaf 7:200]

It was narrated from Sulaymaan ibn Sard that two men were trading insults in the presence of the Prophet (peace and blessings of Allaah be upon them), until the face of one of them turned red. The Prophet (peace and blessings of Allaah be upon him) said,

“I know a word which, if he were to say it, what he is suffering from would go away: ‘A’oodhu Billaahi min al-Shaytaan il-rajeem (I seek refuge with Allaah from the accursed Shaytaan).’” (Narrated by al-Bukhaari, 3108; Muslim, 2610)

2 – Reciting al-Mi’wadhatayn (the last two Soorahs of the Qur’aan, al-Falaq and al-Naas).

It was narrated that Abu Sa’eed al-Khudri (may Allaah be pleased with him) said:

“The Messenger of Allaah (peace and blessings of Allaah be upon him) used to seek refuge with Allaah from the jinn and from the evil eye until the Mi’wadhatayn were revealed, and when they were revealed he started to recite them and not anything else.”

(Narrated by al-Tirmidhi, 2058; he said it is hasan ghareeb. Also narrated by al-Nasaa’i, 5494; Ibn Maajah, 3511. The hadeeth was classed as saheeh by al-Albaani (may Allaah have mercy on him) in Saheeh al-Jaami’, 4905).

3 – Reciting Aayat al-Kursiy

It was narrated that Abu Hurayrah said:

“The Messenger of Allaah (peace and blessings of Allaah be upon him) put me in charge of guarding the zakaah of Ramadaan. Someone came to me and started grabbing handfuls of the food. I took hold of him and said, ‘I will take you to the Messenger of Allaah (peace and blessings of Allaah be upon him).’ He said, ‘I will teach you some words by means of which Allaah will benefit you.’ I said, ‘What are they?’ He said, ‘When you go to your bed, recite this aayah (interpretation of the meaning):

“Allaah! Laa ilaaha illa Huwa (none has the right to be worshipped but He), Al-Hayyul-Qayyoom (the Ever Living, the One Who sustains and protects all that exists)…” [al-Baqarah 2:255] – until he completed the aayah.

Then Allaah will appoint a guard for you who will stay with you and no shaytaan (devil) will come near you until morning.’ The Messenger of Allaah (peace and blessings of Allaah be upon him) asked me, ‘What did your prisoner do last night?’ I said, ‘O Messenger of Allaah, he taught me something, and claimed that Allaah would benefit me by it.’ He said, ‘What was it?’ I said, ‘He taught me to recite Aayat al-Kursiy when I go to bed, and said that no shaytaan would come near me until morning, and that Allaah would appoint a guard for me who would stay with me.’ The Prophet (peace and blessings of Allaah be upon him) said, ‘He told you the truth, although he is an inveterate liar. That was the Shaytaan.’”

(Narrated by al-Bukhaari, 3101)

4 – Reciting Soorat al-Baqarah

It was narrated from Abu Hurayrah that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Do not make your houses like graves, for the Shaytaan runs away from a house in which Soorat al-Baqarah is recited.”(Narrated by Muslim, 780)

5 – The last verses of Soorat al-Baqarah

It was narrated that Abu Mas’ood al-Ansaari said:

“The Messenger of Allaah (peace and blessings of Allaah be upon him) said: ‘Whoever recites the last two verses of Soorat al-Baqarah at night, that will suffice him.’” (Narrated by al-Bukhaari, 4723; Muslim, 807)

It was narrated from al-Nu’maan ibn Basheer (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) said: “Allaah inscribed a book two thousand years before He created the heavens and the earth, from which the last two aayahs of Soorat al-Baqarah were revealed. If they are recited for three nights, no shaytaan (devil)will remain in the house).

(Narrated by al-Tirmidhi, 2882. This hadeeth was classed as saheeh by al-Albaani in Saheeh al-Jaami’, 1799).

6 – Reciting “Laa ilaaha ill-Allaah wahdahu laa shareeka lah, lahu’l-mulk wa lahu’l-hamd wa huwa ‘ala kulli shay’in qadeer (There is no god except Allaah Alone with no partner or associate; His is the Sovereignty and His is the praise, and He is Able to do all things)” one hundred times.

It was narrated from Abu Hurayrah that the Messenger of Allaah (peace and blessings of Allaah be upon him)  said:

“Whoever says “Laa ilaaha ill-Allaah wahdahu laa shareeka lah, lahu’l-mulk wa lahu’l-hamd wa huwa ‘ala kulli shay’in qadeer” one hundred times in the day, will have a reward equivalent to that of freeing ten slaves, one hundred hasanahs (good deeds) will be recorded for him, and one hundred sayi’ahs (bad deeds) will be erased from his record, and it will be protection for him from the Shaytaan for that day, until evening comes. No one could achieve any better than him except the one who does more than he did.”

(narrated by al-Bukhaari, 31119; Muslim, 2691)

7 – Remembering Allaah often (dhikr)

It was narrated from al-Haarith al-Ash’ari that the Prophet (peace and blessings of Allaah be upon him) said:

“Allaah commanded Yahyaa ibn Zakariyah (peace be upon him) five things to follow and to enjoin upon the Children of Israel… and he commanded them to remember Allaah, and the likeness of that is a man who was being pursued by the enemy, until he reached a strong fortress in which he found protection; similarly a man cannot find protection from the Shaytaan except by remembering Allaah…”

(Narrated by al-Tirmidhi, 2863; he said it is hasan saheeh. The hadeeth was classed as saheeh by al-Albaani in Saheeh al-Jaami’, 1724)

8 – The adhaan

It was narrated that Suhayl ibn Abi Saalih said: “My father sent me to Bani Haarithah, and there was with me a slave of ours, or a companion of ours. Someone called out his name from a garden, and the one who was with me looked into the garden and did not see anything. I mentioned that to my father, and he said, ‘If I had known that this was going to happen to you, I would not have sent you. But if you hear a voice then make the call for prayer, for I heard Abu Hurayrah (may Allaah be pleased with him) narrating that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “When the Shaytaan hears the call to prayer, he runs away fast.”’”(Narrated by Muslim, 389).

The word translated here as “runs away fast” may also mean “farting.”

9 – Reciting Qur’aan offers protection against the Shaytaan

Allaah says (interpretation of the meaning):

“And when you (Muhammad) recite the Qur’aan, We put between you and those who believe not in the Hereafter, an invisible veil (or screen their hearts, so they hear or understand it not)[al-Israa’ 17:45]

And Allaah knows best.