4 and half month old rolling on belly to sleep...

Sarah

So my daughter will be 5 months the 12th and she loves to room onto her belly she is pretty good at it but she isnt to good at rolling back on to her back. Well tonight for the first time she decided she wanted to lay on her belly and rolled from her back to her belly by herself... this made me nervous so I was wondering what u moms did if an when ur babies did this. did you leave them on there bellies or did u put them back on there backs?