It follows that a woman’s mahrams are her:

• Husband
• Father (includes grandfathers)
• Father’s brothers
• Mother’s brothers
• Husband’s father (includes husband’s grandfathers)
• Sons
• Husband’s sons
• Brothers
• Brothers’ sons
• Sisters’ sons

Though the following are not to be considered as ‘mahrams’, one does not need to observe complete hijab in front of them:

• Old male servants who lack vigor
• Small children

Some people whom we wrongly assume to be our mahrams:

• Cousins (there are many people married to their first cousins. This is because it is Halal to do so since they are not mahrams.)
• Mothers’ or fathers’ sisters’ husbands
• Mother’s/father’s cousins
• Homosexual Men
• Transgenders (people who identify as a gender they were not biologically born with)

The Guidelines of Allah & His Messenger’s (SallAllaahu ‘alayhi wasallam) with regards to non-mahrams

1. It is forbidden to show one’s beauty/adornments to them:
   
   This means observing complete hijab – covering the entire body, including face & hands (as much as possible) with a loose cloth that does not show the shape of the body and is not transparent. It was narrated from ‘Urwah that ‘Aa’ishah said: “The Messenger of Allaah (peace and blessings of Allah be upon him) used to pray Fajr and the believing women would attend (the prayer) with him, wrapped in their aprons, then they would go back to their houses and no one would recognize them.”  Narrated by al-Bukhaari, 365; Muslim, 645.
   Allah says, ““O Prophet! Tell your wives and your daughters and the women of the believers to draw their cloaks (veils) all over their bodies (i.e., screen themselves completely except the eyes or one eye to see the way). That will be better, that they should be KNOWN (as free respectable women) so as not to be annoyed. And Allah is Ever Oft Forgiving, Most Merciful” [al-Ahzaab 33:59]
   
   
2. It is forbidden to touch them in any way:
   
   A woman shaking hands with a non-mahram man (and vice versa), is haram (prohibited). It is not permitted to take this matter lightly just because one’s relatives or husband’s relatives say so. It was narrated from ‘Urwah that ‘Aa’ishah told him about the bay’ah (oath of allegiance) given by the women: “The hand of the Messenger of Allaah (peace and blessings of Allaah be upon him) never touched the hand of any woman. When he accepted the oath of allegiance from a woman, he would accept her words and then say, ‘Go, for you have sworn your allegiance.’” (Narrated by Muslim, 1866)
   The Prophet (peace be upon him) said: “It is better for one of you to be pierced by a steel pin in his head than to touch the hand of a strange woman.” [Al-Mundhiri mentions that all the narrators of this hadith are trustworthy. Al-Albani classifies it as a good hadith in Ghayah al-Maram (no. 403)]
   
   
3. It is forbidden to be alone with them (Khulwah):
   
   Islam forbids a man or a woman to be alone (have Khulwah) with a non-mahram, even if he/she is teaching the person Qur’aan. This is because the Shaytaan (Satan) would come between them. The Prophet of Islam (peace and blessings of Allah be upon him) said: “No man is alone with a woman but the Shaytaan will be the third one present.”
   
   
4. It is forbidden to talk privately with them
   
   It is impermissible to talk privately with a non-mahram whether on the phone, or through chatting, or email. This is the same as Khulwah, two people communicating to each other PRIVATELY, with no third person being aware of what they are speaking.
   
   
5. It is forbidden to communicate with them without need:
   
   If a woman needs to speak to a man for a genuine reason, or vice versa, then that may be even by sending letters, without having to meet, or they may meet from behind a screen, or in the presence of others so that no khulwah will be involved. This is if both are modest and wear concealing garments.
   
   
6. It is forbidden to talk in a soft voice with them:

   Every Muslim reads and hears in the Book of Allah a verse in which Allah warned the purest of women and the most chaste of wives, and urged them to adhere to virtue, proper etiquette and chastity, and He says, guiding them: “O wives of the Prophet! You are not like any other women. If you keep your duty (to Allah), then be not soft in speech, lest he in whose heart is a disease (of hypocrisy, or evil desire for adultery) should be moved with desire but speak in an honorable manner (al-Ahzaab 33:32)

7. It is forbidden to put on perfume when we are likely to encounter non-mahrams:
   
   The Prophet (peace be upon him) said: “Any woman who puts on perfume then goes and passes by some men to let them find her scent is a type of adulteress.” [Musnad Ahmad, Sunan at Tirmidhi, Sunan Abi Dawaud, and Sunan al-Nasa’i with a sound chain of transmission]
   
   
8. It is forbidden to be in mixed gatherings – where men and women mingle:
   
   This could be a wedding party, or a party in a friend’s house, or schools in education where there is co-existence. We must try out BEST to obey Allah as much as we can. If you are in a co-ed school, then try to go to a school where there are only girls. If you cannot do that, then you must try your best to not to mix with the boys.

   What about family gatherings?
   Shaykh Abd al-Azeez ibn Baaz (may Allah have mercy on him) said, “It is permissible for woman to sit with her husband’s brother or cousins etc., so long as she is wearing proper Islamic hijab, covering her face, hair and all of her body, because she is ‘awrah and a source of temptation, and so long as there is nothing suspect about this sitting with them, and she is not sitting alone with any one of them.
   With regard to sitting alone with one of them, or in a suspicious manner, that is not permissible. It is more important that a woman should observe hijab in front of her husband’s relatives such as his brothers, because the husband’s relatives can enter upon her and sit with her without anyone denouncing that, then that may lead to regrettable consequences.”

Can a Muslim girl have a boyfriend?

If all of the guidelines mentioned are followed- would that leave any chance for a Muslim woman to have a boyfriend?!?!?!
Allah – the All-Knowing (Al-Aleem), All-Wise (Al-Hakeem), the Most Merciful (Ar-Rahmaan], the Most Generous (Al-Kareem), Our Rabb, Who nurtures us, cares for us, teaches us, our Guardian (Al-Wakeel), who protects us, and takes care of all our affairs – is the One Who has given us these limits with respect to our non-mahrams. He is the One Who created us, and He knows what is best for us. Shaytaan, the accursed, wants our hearts to be busy, sad, fearful, drunk in this world, so that we are unable to worship Allah.
What begins as a crush can consume all your waking thoughts and nighttime dreams, to the extent that it distracts and contaminates your worship of Allah – a result which greatly pleases the Shaytaan. Thought leads to speech, speech to proximity, proximity to touching, touching to holding, and all the while, at every step, Shaytaan whispers encouragements to you, justifies and beautifies your actions to you, until your sins accumulate and grow more serious while you perceive them as good or permissible deeds. May Allah protect us all! Sins only bring hurt, heartbreak, sadness, embarrassment, deception. And Shaytaan LOVES for us to go through all these emotions, and for us to be BUSY and PREOCCUPIED with this mirage, that we forget the reality.
If we leave ourselves to sin- then who will protect us? If we do not have Allah as your Guardian, what do you think will happen to us?
Allah says in the Qur’aan, “Bad statements are for bad people (or bad women for bad men) and bad people for bad statements (or bad men for bad women). Good statements are for good people (or good women for good men) and good people for good statements (or good men for good women)” (Surat An-Nur 24:26)

Therefore, we must keep ourselves pure, and Allah will present us with someone pure, while if we engage in shamelessness and indecency, then we will have a similar spouse in the future.