What is the ruling on resorting to the unlawful to obtain things that a father does not buy or a doctor does not give?

A father must spend on his children with what is reasonable and customary. If he refrains from doing so despite his ability, they are permitted to take what suffices them from his wealth without his permission. Based on this, it is permissible for the questioner to take the expenses for her medical treatment and her lawful clothing from her father's money without his knowledge, as long as she does not possess any money herself. As for her question, "Am I resorting to what is forbidden (haram)?" — if she meant taking from her father's money without his knowledge, its ruling has been clarified. If she meant taking from someone else's money without right, such as theft, then it is undoubtedly forbidden. And if she meant deviation and corruption, this is even more gravely forbidden.