my baby is 4 mnth 12 days still she is not rolling but in tummy time full head control..but no rolling she rolls oy half n then stop

A. Rover can happen between the age of 3 to 9 months so you are left with enough time if your child does not do it by completing the time of nine months also then it would be a delay but initially you have six months with the child can definitely learn to roll over the period