Hi, My daughter is just over 4 months old and has started to roll onto her tummy to sleep. I put her to sleep on her back but after a few hours she insists on rolling onto her tummy. Do I need to keep waking her up and insist she still sleeps on her back? She is already sleeping with arms out but in a sleeping bag. I’ve tried to keep her on her back but she just ends up screaming and refusing to go back to sleep unless she is on her tummy.

Most babies will be rolling by 5mths - some as early as 3 - 4mths which is not uncommon.
Many babies then prefer to sleep on their tummy.

It is important that you move your baby from bassinet (if not already in cot) & cease wrapping which you have done.
Also ensure that there is nothing soft or loose in her cot.
This is not something that needs to be stopped, but it is important to make the environment as safe as possible for this to occur.

Red Nose has the following information now that your baby boy is starting to roll.

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.com.au/article/what-do-we-do-now-that-a-baby-has-started-to-roll-ove