Could also be that the parents pick her up every time she cries while on the floor, so she does it because she gets picked up. I would just leave her on the floor for a bit every day (maybe even in a playpen) and when she falls over, leave her to figure it out on her own. Or, show her what to do, but don't do it for her, kwim? Instead of picking her up, help her sit up etc...then gradually stop helping her up and she should do it on her own.