Very normal. Will take weeks for them to learn to roll back. Just have to roll them back to the back. I rememver barely having sleep as my baby kept rolling to tummy during sleep and cried.
It’s normal as they don’t know how to flip back yet. They will slowly learn how to gain strength to flip back. Give time and guide them.
Nothing much except to keep flipping her until she learns how to flip back. Jiayou