Are there things she would like to do, but can't because she doesn't get the opportunity to?

I'm thinking of my own instances of being frustrated about not getting to do my own thing because I have too many responsibilities at home. Are you asking her to do more (even unintentionally - just as a result of riding) because you want to ride? Can you encourage her to take up an activity of some kind (if she doesn't have anything now), and you'll cover her responsibilities in exchange for bike time?