All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
First of all, the son should have accepted the wish of his mother by not marrying you, because obedience to the mother in such a case is an obligation. However, since the marriage had already taken place, then it is not permissible for the mother to ask her son to divorce you unless she has a sound reason for doing so.
Furthermore, your husband is not obliged to obey her and this is not severing ties with kinship, because her ordering him to harm you is a disobedience to Allaah and there is no obedience to a creature in disobeying the Creator. For more benefit, please refer to Fatwa 84942.
Moreover, it is not permissible for the mother to ask her son not to spend the night with his wife and it is not permissible for him to obey her in this regard because this contradicts having good marital relationships and this causes harm whereas the husband is forbidden from harming his wife.
According to the most preponderant opinion of the scholars a husband is obliged to spend the night with his wife according to being affectionate with her and so that the harm of her feeling lonely is removed.
Similarly, the husband is obliged to spend on his wife and provide her with food, drink, clothing and a suitable accommodation, and the wife is not obliged to provide any of these even if she is rich and well-off.
As regards proving evidence of the story of ‘Ebraaheem [Abraham] with the wife of his son Ismaa’eel [Ishmael] then there is no evidence in this. This is because the wife of Ismaa’eel did not know that this guest was the father of her husband in principle, and he did not inform her of this. Rather, he just asked her about her husband and their situation. Then, she complained to him about the lack of the means of sustenance and he knew that she was a complaining wife who was not really pleasing because she was not patient and she was not pleased with Allaah’s Decree, so he ordered his son to divorce her for this reason.
So, how can this be compared to a mother who asks her son to divorce his wife just to satisfy her own desires.
For more benefit, please refer to Fatwa 84056.
Allaah Knows best.