Well since I originally posted this thread Abbie has gotten much more used to tummy time and is starting to show signs of rolling over. I think she may end up rolling back to tummy first, when she's on her back she's started twisting her head over her shoulder and arching her back and twisting towards her head (really hard to describe) but it looks like its just a matter of time till she gets herself flipped over on her tummy. I'll keep you posted. Thanks to everyone for their replies!