How can i make my self look younger?

Im only in middle school but people always think im like 16 years old and i tell them im only a young teen but they say its because i act mature and my body is built like a women but I dont like how men and stuff look at me because they think im older so what can i do to make myself look younger?
I dont wear makeup.

Looking older is good when you’re that age.. It means you’re very beautiful.