Does your gym have a Gauntlet (sp?). I'm not sure if that is the proper word or not but its a certain kind of stair climber. Not all gyms have them but they do wonders.
If she tries to work her way up to 30 min to 40 min even only 3 days a week on this thing... it would really show a difference. Along with her lunges, box jumps and deep squats.
I always get much harder in my butt and quads when I use this on a regular basis. I just joined a new gym this week and they have 2!