Why TF Am I So Teeny Tiny?

I'm 17 and only 5ft 1 and in proportion so really slim compared to everyone else! When we're lined up as a class I look like a mini figurine! It's so hilariously upsetting my parents were average to slightly short height, and all of my siblings have turned out teeny tiny too! it's probably normal but I need support guys, I'm tired of being used as an armrest!
Why TF Am I So Teeny Tiny?
Post Opinion