Sorry if this has been asked 1,000 times! But, my 5 year old DD (almost 6 year old) doesn't have the back flexibility like a few of the other gymnast her age. They go into a back bend, and it's like their hands touch their feet!! I'm truly amazed. They look like rubber bands! Right now, my DD can do all the skills they can do (expect some of their skills are prettier to watch because of their flexible backs). Will it hurt her in the future by not having a back made of rubber?! My DD probably has more strength and power over the flexible back girls. These girls were just born with amazing bending backs!