Sophie is just over 6mths and hasnt rolled over by herself yet. We do all the leg over stuff, toys for encouragment, tummy time etc but she just isnt interested in rolling. She can pretty much sit up by herself, chews everything, drinks like a baby fish, swipes any food passing her, spits farex everywhere -so she is pretty normal. Shes 9-10kg so we wonder if her chubb is not helping- but then DS1 is the same build and rolled at 3.5mths, DS2 rolled at 4mths. Should we be worried?