Is it permissible for the wife to take money from household expenses without her husband's knowledge, due to him not giving her personal allowance and his refusal to let her manage her own money, and is what she did previously considered Haram, and what should she do with it?

A husband must spend on his wife reasonably. The wife is not obligated to spend from her private wealth unless she does so voluntarily. She has the right to dispose of her money without her husband's permission. It is not permissible for a wife to take her husband's money without his knowledge if he is spending reasonably; if she does so, she must return it or seek his forgiveness. However, if the husband takes from her money without her consent, she may take from his money an amount equal to her right.