Baby doesn’t put weight on legs

Anyone else’s baby still not put weight on their arms and legs?

Amelia was 7 months 2 days ago and it f you hold her up by her waist to stand she just bends her legs and they go all floppy. She has a jumperoo and she doesn’t bounce she just plays with the toys. If I hold her hands and pull her to stand on my lap she will stand but I feel like I’m holding her up rather than her doing the work if that’s makes sense?

She also can’t push her chest up with her arms and when she does tummy time she’s still flat on her chest and not on her elbows or hands.

I’m starting to get worried now both her brothers were pulling themselves up to stand and on their hands and knees trying to crawl at this age.

She’s got physio this afternoon for something else so I’ll mention it to them but I just wondered if anyone else’s babies were like this still?

She does sit, rolls both ways etc