Livvy will roll when she is good and ready! LOL. There is no time frame for things like this to start happening. Lindsay was only just roling at five months too and I never worried about it. But the girls were doing all of it much earlier. I remember when Erin was born, another playgroup Mum had a little girl three weeks older and she got worried when Erin was crawling at nearly 5 months and her little one hadn't started to roll yet.

Milestones are reached at different times for different babies and unless you think there is something phsyically wrong with her, then try not to worry, she will do it in her own time. She is probably just happy to lay still and watch everyone.