My daughter's right waist was curvier before and now the left side is curvier? What's happening?? Is it because of puberty??

Have her doctor. examine her. I'm not sure how old she is, but if she is going through puberty, and growing a lot, she could have scoliosis (a sideways curve of the spine) or her legs could be different lengths. A simple exam (and possibly an X-ray) will be able to diagnose the issue, if there is one.