Is a wife considered sinful for not loving her mother-in-law? And is a wife's lack of love for her mother-in-law a reason for Allah to punish her, knowing that she treats her well? And is the husband obligated to bring his mother to live with them?

There is no harm in negative feelings towards the husband's mother, as long as the wife treats her well outwardly and these feelings are not translated into actions or words that harm her. This is because Allah overlooks inner thoughts as long as they are not acted upon or spoken. However, it was wrong to express these feelings to the husband. It is permissible for a woman to call her husband's mother "my mother" out of respect and appreciation, unlike calling a non-husband "my husband," due to the religious prohibitions associated with that. It is not obligatory for the husband to house his mother with him; what is obligatory is to be dutiful and kind to her. It is the wife's right to have an independent dwelling not shared by anyone, but it is better for the wife to accept her husband's mother living with them and to be patient with her, as an act of kindness towards her husband.