The mahr is the wife's exclusive property, given to her and not to her family: "And give the women their dowries graciously; but if they give up willingly to you anything of it, then take it in satisfaction and ease" (Quran 4:4) — the permission to take from it is conditional on her own free, willing gift, not on pressure from a father or husband. Allah further forbids a husband from clawing it back even when he divorces her to marry another: "If you have given one of them a great amount, do not take from it anything. Would you take it in slander and manifest sin? And how could you take it while you have gone in unto each other?" (Quran 4:20-21). Her wealth in general remains hers, for "men will have a share of what they have earned, and women will have a share of what they have earned" (Quran 4:32), so her salary or inheritance is not automatically the husband's. Customs in which the father pockets the mahr, or the husband "borrows" it and never returns it, are a wrongful consumption of another's wealth and must be corrected — though a wife who freely chooses to give any of it to whomever she wishes is entirely within her right.
Q&A · Marriage & Divorce
Who actually owns the mahr — can the bride's father or her husband take it from her?
Evidence — the daleel
On deen2u
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.