When do babies stand up from sitting?

[ElyElyOy]

My son is 15 months and walking reasonably ok. However he can’t stand up from sitting. I’ve noticed other children (who look around his age and younger) fall over and just stand up, but my son has to find something to pull himself up on.

We are at the Drs in a few weeks so I can mention it then, but I wasn’t sure if I’m just miss-judging the age of the other children or expecting too much.

my son was 9 months. my nephew 15 months. dont stress hell figure it out, it takes a lot of leg strength too so try n let him walk up the staris as much as possible. my sons been doing this with me behind him since he was 10 months. he leads the way to bed. now he can actually step up and doesnt need to go on his knees to climb up.