|>>|| No. 26514
My missus still gets this and she's 30 this year. A bus driver wanted to sell her an under 16s ticket the other month. I don't get it, she looks young but more like 20ish than a teenager to me, though I've known her since we were both 13 so maybe that's why. She's short like you though, too, though I'd have thought the massive boobs or the lip piercing would have given the game away too, but there you go.
For her part, she straightens her curly hair, wears prominent lipstick and eye shadow/liner (sorry I don't know exactly what she does because I'm a bloke) and wears a lot of blouses and shirts and such. She also wears boots often which make her a little taller, but I assume almost all short women already do that. I can ask her directly later for more details, if you'd like, but her eye makeup definitely makes her look older.
I suspect a lot of it comes from the fact it's weighing on you so heavily, though - the missus is confident and decisive, doesn't particularly give a shit anymore, and that comes across in just about everything she does, if she's talking there's no way anyone would mistake her for that young because she talks like someone who has their shit together - she doesn't, particularly, but she sounds like she does. If you're in your head about this, and it's knocking your confidence, then that might well have the effect of making you look even younger as you shrink into yourself. Assertiveness and directness makes you look so much older, though I appreciate it's a difficult attitude to just suddenly adopt. Fake it till you make it, though.
Sorry that I'm mostly rambling here, but I hope there's something of use to you in there.