DD is 5 months and started rolling onto her side about a month ago. She did it quite a lot, though only to the right, and then stopped entirely for a couple of weeks. She now does it again, and still only to the right, but is showing absolutely no signs of wanting to roll right over onto her tummy. She doesn't like tummy time, though will tolerate it for a lot longer than she used to, but will start grunting within a couple of minutes and then cry. However, for the past few weeks she has been desperately trying to sit up forward by doing abdominal crunch type movements (bringing her head and her knees up)!
So - should I be worried? Developmental milestones seem to suggest she should be rolling over fully by now. Is there anything I can do to encourage her to do this?