from back to tummy, it can take as long as 6 months... my girl is almost 4 months and can only do tummy to back. tried moving her arm out of the way so she could figure it out, but that upset her even more lol!! they'll figure it out in time(:
No worries mama, bigger baby needs to build more strength! Every baby develops at different rates, everywhere I've read says 5.5 months is the norm for rolling...my girl rolled both ways by 3 months but she's 4.5 months old and roughly 15lbs, not 20 so she's got a size advantage! Don't panic, just follow baby's cues and don't put too much pressure, your baby will figure it all out whether we try and rush them or not ;) if you're really concerned, bring it up at her next appointment, but I'm sure there is absolutely NOTHING wrong with your baby developmentally 😄
Weight can play a part in it. The heavier the babes is the harder it is for them to learn. My nephew was a chunk and it was harder for him to learn how to crawl and walk.
Every baby is different but I'd definitely keep practicing. My son was rolling from belly to back and back to belly at 3 months. Just do more tummy time! Your baby will get it 😊