Sleep positioning

So, I know babies are supposed to sleep on their backs....but....my little girl is most comfortable on her side or tummy. When I was a baby my mom was instructed to put my on my stomach in the crib, when my friend had her kids a side sleeper was used, and now it’s back so clearly this changes.

Does anyone break with guidelines and put their baby on their tummy or side? I’m worried about transitioning her to the crib when she spits up on her back & doesn’t sleep well.

For cuteness I’ll add a photo of baby girls 7 week photo outtake!