My 4month old has mastered back to tummy rolling but hasn’t been able to roll from tummy to back as yet. We have had major sleep issues since, as she constantly wants to sleep on her tummy. Is it ok to leave her on her tummy to sleep if she rolls there herself? Or do we need to roll her back every time? We are up hourly at the moment rolling her back and it is exhausting!

Most babies will be rolling over by 4- 5 months…...some earlier, some later.                                                                    This is normal as babies grow & become stronger.
Many babies then prefer to sleep on their tummy or side.
This is not something that needs to be stopped. It is important to make her environment as safe as possible.

**Firstly, now that your baby is rolling, she needs to be in her cot for all sleeps & not wrapped or swaddled, if not already in place.
Baby needs arms free & space of the cot to roll safely.
Increase tummy time when awake to help build upper body strength.
Ensure that the cot mattress is firm & flat & there is nothing soft or loose in her cot.

As you have found, there is not much to be achieved by trying to roll her back from her tummy.
**Always continue to place baby on back to sleep.

Red Nose has the following general information now that she is rolling.

Give baby extra tummy time to play when awake and supervised as this helps baby to develop stronger neck and upper body muscles which in turn enables them to roll back over.
Make sure that baby is on a firm and well-fitting mattress that is flat (not tilted or elevated).
Make sure that baby’s face and head remains uncovered (do not use lambswool, doonas, pillows, cot bumpers or soft toys)

As babies grow and develop they become very active and learn to roll around the cot.
At this time, continue to put them on the back at the start of sleep time, but let them find their own position of comfort.
By this stage it is not necessary to wake during the night to turn baby over to the back position

Do not use any devices designed to keep baby in a particular sleep position.
https://rednose.org.au/article/what-do-we-do-now-that-a-baby-has-started-to-roll-over