In a divorce, would my mother have an upper hand over my father?

My mother and father have been married 23 years, and for some unknown reason my father tells my mother, he is done with the marriage (in about 3 weeks).. My dad said it was that my mom is insecure.. Anyhow, my parents have 3 kids (11,17, and me 21).. they own a company together.. and have a house, a bmw, a nissan suv, 2 08' ford trucks, a boat/yacht, a timeshare, and other stuff.. My mom thinks she stands to lose everything if she files for a divorce first, and my dad just remains at her home.. and will not move out.. So wtf? What can she do? Will she lose everything if she files for divorce? Or does she have an upperhand being a mother of 2 kids still living at home? Apart from the financial aspects of their company she doesn't have a side job..