Is a wife obligated to serve her husband's mother, and what is the ruling on reconciling them after it has become impossible? And is it permissible for the son to live in a separate house from his mother in this situation?

A woman's service to her husband and his family varies according to the prevailing custom in the country. If the custom obliges her to serve, then she must do so. However, if the custom dictates that she be served and provided with a maid, then she is not obliged to serve. The husband should treat her kindly and provide financial assistance to encourage his wife to serve willingly. If the husband lives with his mother, there is no harm in him moving to an independent home if his mother permits it. Otherwise, he must remain and be patient, and try to reconcile between his wife and mother through financial assistance and gifts.