Changing bone structure after puberty?

Not sure if this is the right subreddit for a question like this..

But long story short, I didn't eat much growing up as a kid and I'm beginning to think that mightve been the reason why my wrists and bone structure is really skinny/frail.

I'm reasonably tall but I have that very lanky look, and now that I'm older, I'm realizing there's not a lot of people that are as thin framed as I am.

Unless I'm completely mistaken and everyone's bone structure (all things equal) are the same and it's just overlying muscle/fat, but I'm also quite underweight which probably plays a big role.

Is there any way to increase bone density or width after puberty if I improve my diet at this point or am I cooked?

P.S. my family is on the heavier side so not sure how much of this is genetics