DD is a little over 7 months and the past few nights, she's rolled herself over to sleeping on her belly. My first thought was "no big deal" she's old enough now for me not to worry. But, her head wasn't completely to the side, her head was about halfway face down into the mattress - and breathing just fine. But this made me a little nervous so I just tried to roll her back onto her back. Well, that just woke her up! And, she seems to sleep much better on her belly - - I'm all about more sleep for us if this is actually ok?