DD2 is 11mo.
She rolled over once at 6 months and never again. When put on her tummy she will try to move but can't bring her legs up and usually just gives up. She can't bear any weight on her legs.
She can sit well and started bottom shuffling about 3 weeks ago. She will sit quite happily with her legs far apart and bend herself in half. She can even rest her head on the floor in this position.
Is this anything to worry about?