My 12 year old daughter has a slight uneven waist curved?? is this puberty hormones??

Depends: Depends on what you mean by curved. Could be normal, but if you are concerned, she should be examined.

Time for a visit: To me an uneven waist suggests she is developing scoliosis.This is most common during periods of more rapid growth as the vertebrae get taller and may not stack up correctly. Catch it early and sometimes therapy/bracing can prevent the need for surgery later on.