My Mother In Law Is 82 And Has Been Showing

My mother in law is 82 and has been showing unearned anger toward my husband and her daughter. Wanted my husband to do work at her house and the next day was acting unusual. Crying all day making herself sick and 2 weeks later is still acting aggressively toward my husband. Could this be caused by a stroke. She has an aneurysm and is supposed to remain calm. This is unusual