Well... I suppose you don't need more than one guess. Yesterday, when Claire got up from her nap, we were playing in her crib. She's not a big fan of being on her stomach when on the floor, but likes it better in her crib. I put her on her stomach and she pushed herself up on her arms and then I think the weight of that big noggin just pulled her over to her back. The first time she did it, she looked up at me with a look of complete astonishment. I flipped her back to her stomach and she rolled right over to her back. I took her downstairs and tried to film her rolling over, but she was too speedy for me. I couldn't put her down and pick up the camera before she would already be on her back. We'll have to try it this weekend when we have 4 hands instead of my 2.
She seems like a different little girl this week. She actually likes to sit by herself in things when she's awake - and she let me get my hair cut yesterday sitting like an angel for two hours in her carseat. Before long, I'll be talking about her crawling and walking, but for now, I think it's pretty neat to watch her roll over.