I can understand why this hurt. I would feel that, too. But I read it a little bit differently. I read it not that she has to protect her family from YOU, but that she has to protect them from her own desire to always be there for you or her tendency to have blurred boundaries between home and work. I'm not saying she should have shared that with you, but it sounds like some sort of internal thing that she has to manage, so that everyone in her life gets enough (or as much as she can reasonably give) from her. Conversely, she also has to have boundaries around her family, so that her family life doesn't spill over too much into her work with clients.