5 month old sleeping on belly

So my LO (5 months) new fav thing to do is roll on to her tummy to sleep. I place her on her back in her crib or pack n play, and she almost immediately will roll over to her tummy. Her head is turned to the side ofc, but it makes me a little nervous bc she hasn’t fully mastered rolling front to back quite yet. :/ is she okay to sleep like this? Idk how I would even prevent it without watching her throughout the night which really isn’t an option bc I work full time and need sleep… 😅