1. Ruling on cutting the hair of head:
There is no evidence that suggests the cutting of women's hair is disallowed. What is forbidden is shaving it. It is permissible to shorten the length of the hair, however, shaving it entirely is prohibited and forbidden. There is nothing wrong with trimming the hair.
But the cutting of hair must be done properly and in a manner that is permissible according to shareeah. Also, If it pleases the woman and her husband that she must do it.
So if the hair is very long or thick, and the woman cuts it to reduce its length or volume, that doesn’t matter. Cutting some of it will make it more beautiful, which will please both the woman and her husband. So we do not know of any reason to disallow that. But shaving it all together is not permissible, except in the case of sickness. And Allaah is the Source of strength.
It was narrated in Saheeh Muslim that Abu Salamah ibn ‘Abd al-Rahman said: “The wives of the Prophet (peace and blessings of Allaah be upon him) used to cut their hair until it came just below their ears.” (al-Hayd, 320)
Al-Nawawi said: this indicates that it is permissible for women to cut their hair short.
The hairstyle too must not resemble kaafir women and immoral people.
It is not permissible for a woman to cut her hair short in the back and leave the sides longer, because this involves disfiguring and fooling about with her hair which is part of her beauty, and it also involves imitating the kaafir women. This prohibition also applies to haircuts which are named after kaafir women or animals, like the “Diana” cut, named after a kaafir women, or the “lion” cut or “mouse” cut, because it is haraam to imitate the kaafirs or to imitate animals, and because that involves fooling about with a woman’s hair which is part of her beauty.
2. Removing facial hair.
With regard to hair which is abnormal, because it grows in places where hair does not usually grow.
With regard to hair which is abnormal, because it grows in places where hair does not usually grow, such as a woman having a mustache or hair growing on her cheeks, there is nothing wrong with removing this, because it is abnormal and is disfiguring to the woman.
It is okay for a woman to remove the facial hair including upper lip, chin or sideburns, thighs, calves and arms. What is prohibited is eyebrows.
What is the ruling on a woman removing hair from her body; if it is permissible, then who is allowed to do that for her?
It is permissible for a woman to remove any hair except the eyebrows and the hair of her head. It is not permissible for her to remove those, or to remove anything from the eyebrows whether by shaving or any other means. She, her husband or one of her mahrams may do that for her, with regard to the parts of the body that they are permitted to see; or another woman may do that, with regard to the parts of the body that she is permitted to see
The hair of the private parts and the thighs may not be seen by either another woman or a mahram.
It is forbidden for a woman to remove her eyebrows or part of them by any means, whether it be by shaving, cutting, using a depilatory substance, because this constitutes the plucking for which the Prophet (peace and blessings of Allaah be upon him) cursed the one who does it, i.e., the women who pluck all or part of her eyebrows, claiming that it is for the purpose of beautification, or the woman who does that for her. This is changing the creation of Allaah which the Shaytaan promised to enjoin upon the sons of Adam.
And Allah knows best.
May He guide us all.