Sleeping Positions

Last night I checked on Cassie before going to bed, she was sleeping on her back with her blanket under her and her arm and leg hanging out of the slats in her crib. Everytime we see her sleeping on her back Matt and I both kinda freak. As an infant she could NOT sleep on her back because she would block her airway as a result of the receded jaw. Back then you could hear her tounge block her airway and she would have labored breathing and her rib muscles would retract in an effort to breath. Her jaw has grown out now so this isn't a problem anymore but we still lay her down on her tummy to sleep and it is her preferred position to be in,however when she rolls to her back it still freaks us out. My first reaction last night was to put my hand on her chest to make sure she was still breathing and then I rolled her back to her tummy. Yes...we are nervous nellys now even though all sleep studys say she is fine! I joke with Matt that even when she is 16 we will be rolling her from her back to her tummy.