How to deal with a workaholic boss

My boss is a workaolic, she stays late until 7-9PM almost every day. I know that this is not the life style I want and I am a mom and have young kids to take care, so I try to leave the office right after 5. She is not happy about that and complained about it once. I do my job well and finish things on time, she did give me a very good review though. But this issue has led a not very good relationship between us and I do feel discouraged. What will you do in that situation?

Thanks in advance!