Is it permissible for the wife to take the dower (mahr) after she has demanded divorce and has actually been divorced?

It is not permissible for the wife to seek divorce without a legitimate Shar'i reason, nor for her mother to persuade her to do so. What the husband did by taking back the dowry in exchange for the divorce is permissible, and the khul' (divorce at the instance of the wife) is effective even if a long time has passed. It is permissible to perform khul' with the wife for more than what was paid to her if she agrees and is of sound mind and has reached puberty. If the wife is young or of unsound judgment, her khul' is not valid unless someone else commits to paying the amount on her behalf.