It may be a common problem but each solution is going to be different. Before you have a solution, you need to understand the problem. Listen to her. Why does she think you work too much? What would she prefer you do (spend time with her is too generic: she most likely has specific issues in mind. ASK).

I can't stress this enough: listen to her. Listen to what she's saying, not just what you expect her to say or what you think she's saying. Actually clear your mind and listen. Then the two of you can start to figure out what to do about it.