YES YES YES YES YES!!
However, flexibility is only one small part of being a cheerleader! You should carry a certain attitude and be kind to everyone, and remember you're not at game for yourselves- you're there for the team that's playing! :D
Also, just keep in mind that as a cheerleader, you probably will have a LOT of practice and other after school activities/ service. As a cheerleader, you're an essential part of your student leadership group!!
Anyways, you should go ahead and try out! REMEMBER TO SMILE!! ALWAYS SMILE IN CHEER, COACHES LOVE IT!!
Best of luck!!
- CheerlessCheerleader