Back is best for babies but we know how much Luna likes sleeping on her tummy so during nap time we have been letting her just zonk out with her bum in the air. She looooooves it. Her two sisters really preferred being on their backs and on their side, so Luna is the first of the girls to do this face down thing so much.
At night Luna has no choice but to be on her back since it’s safest for baby. She’s really regulated her sleep now that she is two months old. These days, she can sleep from about 7:00pm to four or five in the morning without getting up. It’s good progress for her, so hopefully she’s slowly working her way to to sleeping all the way through the night on her own.