What is the way to support a wife in receiving her inheritance from her father, which her mother refuses to give her, and what should the husband do about this?

We advise you to embrace Islam, for it is the religion Allah has chosen for His servants. Your Muslim wife is not permissible for you as long as you are not a Muslim. Her father erred by accepting you as her husband, as it is unanimously impermissible for a Muslim woman to marry a non-Muslim. Allah Almighty says: "And do not marry [your daughters] to idolaters until they believe," and "Neither are they [the believing women] lawful for them [the disbelievers], nor are they [the disbelievers] lawful for them [the believing women]." Therefore, it is not permissible for you to remain her husband, nor is it permissible for her to remain with you. As for your children, they are Muslims, following their mother.

If you embrace Islam, you should عقد a new marriage contract with this woman, with her consent and the consent of her Muslim guardian.

As for the mother depriving her daughter of the lawful inheritance from her father, this is not permissible. Allah Himself divided the inheritance: for the daughter, half of her father's inheritance if she is one, and two-thirds if they are more than one without a brother. And for the male, the share of two females if there is a brother. The wife receives one-eighth in this case.