Concerned about milestones

I'm a first time mom, (I have 2 step kids but met them when the youngest was almost 2)

My daughter is 7 months. She does spend most of the time (since birth) on her tummy as she loves it. However I find though she seems to have the strength to hit certain milestones it seems like she just refuses.

Sitting up - can do it but is still wobbly, likes to throw her head back almost like a game, she laughs.

Crawling - she can move in circles and backwards while on her tummy but won't go forward, and is starting to go on her knees and also can do planks but won't do it unless she's upset.

Rolling belly to back - she has never done this, though she gets herself around to do it just never completes

Rolling back to belly - she's been doing this since 2 months old but gets very upset when she does it and doesn't do it often (she almost fell off the couch accidentally with daddy once but he caught her in time and she never did it much after this)

I've asked the doctor and I'm told "she will get there" but I cant help but worry still (hes given me incorrect information before, working on a new doctor) is this all normal? Or should I be concerned?

Picture of my girl who turned 7 months on the 25th 💜