I bet you get a good workout from every time you ride, too....
Do you spend a lot of time with her outside, I mean taking nice rides in the cou try and do you maybe have a companion with you?
That speeds them up usually, and when you do little training on the trail, they get pretty good though, too.
I even work collection or sidepassing and lots more on the trail, it keeps them motivated. Maybe that helps your girl to get peped up?!