My 4 month old has started rolling back to tummy she was already rolling tummy to back from about 10 weeks . But now that she can go back to tummy she rolls over every time you lay her in the cot to bed . I read of your website that as long as they roll both ways that if they roll in there sleep that is okay to leave them and as long as you put them to sleep on there back my question thought is what the definition of putting to sleep on back cause I’ll lay her on her back to sleep and I’ll start patting her to sleep but she immediately roll over and go to decide to go to sleep on her tummy I’m just not sure if that okay or do I have to keep rolling her over and patting her until she fully asleep then if she rolls over then it okay to leave her like that . Hope my question make sense thanks

It is important to always place baby on their back for sleep, but allow them to find their own position of comfort.
If she immediately rolls to her tummy herself, & is rolling both ways, then it is ok to leave her on tummy for sleep.

This is a summary of the Red Nose information.
Cease wrapping/swaddling if baby 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
https://rednose.org.au/article/what-do-we-do-now-that-a-baby-has-started-to-roll-over