Whether or not your parents were still married, your mother is entitled to your father's Social Security benefits. However, since there was no formal divorce granted, she was still legally his wife. As to specific benefits that she is entitled to, here are a links to a site that you will find to be of help: https://www.ssa.gov/planners/survivors/ifyou.htmlhttps://faq.ssa.gov/link/portal/34011/34019/Article/3766/Who-can-get-Social-Security-survivors-benefits-and-how-do-I-apply