Opinions?

I am 17, 5'3, and weigh 135.

My family has a fat gene, plenty of us are heavier set in my family. And not that I would mind being bigger and I love bigger women bc they're beautiful and know how to work it. My mom struggles with losing the weight and constantly has to be on a diet to get ANY weight off and it comes back if she doesn't diet. But I just want to know if I'm overweight for my age and height? I don't want to be any bigger than I am and I go to the gym often and never lose any. Everyone says I'm skinny and pretty but I want my belly to be flat.