Hi, my little one is almost 5 months. Her new favourite thing is to roll onto her belly during play time. She hasn't quite figured out how to roll back confidently on her own yet. She keeps rolling onto her side for sleep. She stirs and often wakes when I role her back onto her back and passed few nights have basically been sleepless for me. Should I keep trying to roll her back or let her be on her side?

Red Nose recommendations are to “always place baby on back for sleep” not baby must always sleep on their back.
https://rednose.org.au/article/red-nose-safe-sleeping-recommendations

Most babies will be rolling over by 4- 5 months. Some earlier, some later.
This is very normal as babies grow & become stronger.
Many babies then prefer to sleep on their side or tummy.
This is not something that needs to be stopped. It is important to make the “new” environment as safe as possible.
https://rednose.org.au/article/what-do-we-do-now-that-a-baby-has-started-to-roll-over  (please read full article)

Is she in a cot or bassinet?
Are you still wrapping/swaddling or does she have arms free?
How does she go with tummy time when awake?
Is she holding her head &/or reaching for toys?

Tummy time is important for strengthening upper body muscles required for rolling well.
Rather than placing her on her back for play, place her on her tummy as much as possible.

Parents are not expected to sit up all night observing baby. This is not achievable.
Let me know your replies to the above questions, then I can respond more specifically for you.