My baby is sleeping on her stomach

She is 4 months old and she recently learned how to roll over. Now, whenever she wakes up, she puts herself back to sleep by rolling to her side or stomach. 😑 See pic below.

Is it ok to leave her like this or no? I always move her to her back again, but I sometimes wake her up in the process and I'm wondering if I can just leave her.

EDIT: There are no pillows or blankets in there, although I can see what everyone thinks is a pillow. That's just the back of her bassinet. She's currently in a bassinet and she's wearing a sleep sack… not a swaddle. Both arms are free.

Thank you all for your comments! I think I will continue to roll her to her back until she is able to do it on her own. Until then I won't be leaving her on her stomach... especially because she's in a bassinet that has fabric sides so I worry a bit about restricted breathing if her face get smashed up against the side.