Each sport has a preferred build. Skaters can be taller than gymnasts.
This is my own experience, and every parent has to do as they feel is right for them and their kid. With my first child, she did everything during her elementary school years. Competitive dance, horseback riding, and some skating. Go, go, go. She was soooo tired in school, and this set her back. I overfilled her glass, and she had no time to just be a kid and hang out with her friends. Now, she's 14 and burnt out on dance. Never going back, burnt out. She'll come skate, a little. But, she loves to horseback ride. So, once a week she rides a horse and one weekend a month she helps out at an equestrian center for special needs. Riding is 4x as expensive as figure skating, so that's why it's once a week. It also has one of the highest incidence of becoming paralyzed, like gymnastics. Baby #2 came and he does mite hockey and a learn to skate class. He skates two to three days a week. With one in 2nd and the other in the 8th grade, I can't be gone ever single night with activities (spouse travels and I'd have to take both with me). They need time to be kids. Take a cue from her, and watch her closely. Her needs are going to change as she gets older and school becomes more demanding.
Skating, dance or gymnastics is really tiring. I can skate hard for an hour a day, but I'm sometimes "too pooped" to do much afterwards but Facebook and check skating forums.com.