I have a question about clothing. What can a female wear at house in front of her parents and sisters??

There are no clear texts that deal with this matter, and for this reason there is much difference of opinion among scholars regarding it. Some jurists invent chains of reasoning to justify very strict rules in this regard, forgetting that when the Quran and the Sunnah are silent or vague on a certain matter, it is because that matter is being left to a person’s own discretion. This is the opinion of the scholar Ibn Baaz, may God have mercy on him. He says that a woman can wear what is considered culturally appropriate and non-scandalous in front of their close male relatives (“mahrams”, males who are prohibited by Islamic law from marrying her) and female relatives and female friends.

Examples he gives of things that are permissible to show to mahrams are these: The head (i.e. including hair), neck, the ear, the arms and hands, and the lower part of the legs (everything below the calves). He also says it is permissible for a woman to relax the rules for certain emergencies and needs, for example she can breastfeed in front of mahrams if this is considered culturally appropriate by the community the person lives in, meaning she can do it even if there is a chance they will see her cleavage and part of her breast if they look in her direction.

These rules apply even if these mahrams are not Muslim, as the major Islamic schools of jurisprudence do not differentiate between Muslim and non-Muslim mahram relatives in most matters, including this matter, according to a ruling by professor Fahd bin Abdulrahman al-Yahya of Qassim University, Saudi Arabia.

In short, the Quran and the Sunnah do not provide specific rules for how a woman should dress in such circumstances. It is expected that (religiously devout) people can find for themselves a middle road between being too strict and being too lax. Since life is complicated, what one does in one situation may not work for them in another. A woman can observe a stricter dress code in front of an uncle they see once or twice a year or who they do not trust, while in front of their brother they may wear what is comfortable and doesn’t get in the way. Or a woman may feel comfortable breastfeeding in front of her brother, but she may not feel comfortable doing this in front of her father. Or she may dress in a more relaxed manner in front of a close female friend while being more strict in front of distant friends.