What do you mean by they seem to tumble better? Do they have more tumbling skills or do they seem to have better form? Often times cheerleaders will have more skills because they are working solely on tumbling, not other parts of gymnastics, and they are looking to just get the skills, not perfect them.
If tumbling is being coached by a gymnastics coach, it's not so much a problem but often it is not and the coach doesn't have the background experience to teach the skills properly. Girls are often told to "just chuck it". And even if the girl has learned it correctly in a tumbling class or at gym, if she is practicing it in cheer without proper guidance and correction, she is likely to gradually pick up bad form. And, whereas most cheerleading skills end with just that one skill, and therefore a girl can get away with a messy backhandspring or back tuck, gymnastics has to build upon those skills for higher level tumbling. If the skill was taught incorrectly in the first place, the girl will have a harder time relearning it to build upon it. Also, too often, in cheer practice, the skills are taught on a regular floor with mats, instead of on a trampoline, tumbletrack and/or spring floor. Not only does it make it harder, but it increases the risk of injury.
Having a cheer program inside a gymnastics program seems to work the best, where the gym coaches are teaching the tumbling and better equipment is available. As long as you are minimizing the risk of her learning skills wrong, minimizing her risk of injury, and she has a qualified coach teaching her the tumbling skills, let her try it out.
