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.
The scholars stated that a husband is obliged to provide his wife with an accommodation where she is not harmed by anyone, be it her mother in-law or else. Therefore, if she refuses her mother in-law to live with her in her own house, she has the right to do so, especially if she is harmed by her mother in-law. However, if the husband wants to accommodate his mother in a section in his house which has separate amenities, then he may do so and the wife has no right to disapprove of this.
Generally, a wife should help her husband be dutiful to his mother, as this strengthens the marital relationship between her and him.
Allaah Knows best.