I would have guessed she was about 24.
The girl in the OP looks 15 to the eyes of this poster who has worked with teenagers for eight years now. Sure, she’s a mature looking 15, made up to look picture perfect, but she’s still 15 looking. I’ve got plenty of students that share similar looks.
Now, if you want to talk someone who doesn’t look their age at all, let’s talk about Courtney Stodden- 16 year old child bride of actor Doug Hutchinson. Ok, she’s like, 17 now, but she’s still under age and likes to do really tashy photoshoots. Go ahead, Google some and wonder to yourself how a 16 and 17 year old child can look so much like a 45 year old smoker.
I blame chicken nuggets.
Sure she does - a 15 year old made up for a photo-shoot, but I could still buy 15 easily.
Ditto as above - I could totally believe 12.
Yeppers. When you compare the first two to poor Courtney, they look positively breezy and fresh. I have no idea how a 16 (17) year old girl can make herself look so used up and hard. 
Push up Bra - Check
Professional Make Up - Check
Professional Lighting - Check
Making a child look like a woman - Priceless
When I was 15, my tits were that awesome without a bra. Sigh, memories. . .
We demand to see the long form birth certificate.
Right. From the photograph alone, not having the benefit to gage level of maturity from a conversation, I could believe that’s a picture of someone who’s 15 but I could equally as well believe she were 21, if all I had were your say-so. They sure are feeding them well Down Under :p.
As to ability of someone 15 to “pass” for 18+ if others do not do really put a lot of effort into their due diligence, two words: Traci Lords.
Somehow, fiftysomething Doug Hutchinson has manged to become even creepier than Eugene Toombs, the terrifying character he played in the X-Files episode “Squeeze”.
She does look like a fifteen-year-old with lots of make-up on. That’s not the same as what adults often expect 15-year-olds to look like - good god, Jim, that’s a child!
The 12-year-old just looks 12. She doesn’t even look old for 12.
But then, my 13-year-old daughter and her friends have to carry ID to prove they are as young as they say they are because nobody ever believes them, and they don’t wear make-up or try to look or act old, they just went through puberty early and are tall, like many kids these days.
At her Guides (Girl Scouts) troop there was a six foot tall busty ten-year-old who, like my daughter, was actually rather innocent and young for her age. It was a bit odd watching them all playing musical chairs with child-like gusto when they were all taller than me, and I’m not short.
Yeah well, to me they came with that package I gained in 7th grade, in 3 months, along with every other curve in my body. I’m surprised by the “early 20’s… stop gaining height” bit: I only know a couple of women who were still growing beyond 18, and both are extremely tall.
Man, I’d never heard of her (or him) before this and marvel at how anyone in their right mind would want to do this to themselves (age so fast, look so hard and trashy) or want to marry them to begin with. Love is not only blind, it can be tasteless. Somehow, I don’t envy their kids.
Reminds me of the (very voluptuous) 15 year old who was recently not permitted to roam Disney World in her Tinkerbell costume…she must eat a lot of chicken 
Reminds me of that ridiculous Can a minor ever look older than 18 thread we had a while back.
I’d say the minor in the OP definitely qualifies.
In the red dress, theyre squished up. Boobs dont have that bulbage over the top naturally. Its either a push up, or implant
It seems to me that the farther adults get away from childhood, the more childish they think children are or should be.
People are so hung up insisting that a 15 year old is “just a kid!” that they start to believe that they should look like 11 year olds.
She is a young woman. I am sure she is not as intellectually and emotionally mature as a 25 year old, but she is still a young woman.
We have absolute morons that are 30, but they don’t get called children.
People nowadays often do not look their age… I am almost 20 and people think I am 16. It happens both ways.
Plural?
Yeah, believe it or not, most of us have two!
She does to me.