Limewave, please do not feel guilty. Anything you do for you, you are, by extension, doing for your family.
Heck, I got babysitters so I could teach my 5 AM aerobics class when my DH was out of town... the babysitter stayed until I came home, showered, got ready for work, and then my nanny came so I could go to work. Oh, the other moms in my play group just shook their heads. My mom, though, totally understood, as she was very athletic, but lived in a time when women just didn't do endurance stuff.
Just think of what a good role model you are, especially for your daughter. Both of my kids are extremely fit and active adults. It just is "the normal way" for them.