If you’re willing, go cold turkey and start sleep training her on the bed now. My little one also flips onto her tummy before she can fall asleep. I leave her alone because she’s more than capable of breathing well while on her tummy already (I watch her on the baby monitor for every nap and every night while I’m awake) .. and her cot has nothing that can suffocate her. You can read up on the various methods of sleep training and choose the method that suits your family:)