Maybe someone can help me out with this, where in MCU canon is it established that Wanda is/was a teenager? I always assumed she was like, early twenties at the start of AOU. I get that she’s had a traumatic childhood but she neither looks nor acts like a teenager, however I’m prepared to be corrected on this?
I do think it’s plausible she was 18 in AoU. I would argue she’s at least coded as being no older than early 20s. However, she can’t be younger than 17, since she was 10 when her parents died and Tony didn’t stop making weapons until 2008. She is likely meant to be a bit older though.
The people who think she’s like still 17 even in IW are either kids themselves who think that that’s older than it is, or people not getting that her being referred to as a kid has more to do with her relative inexperience than actual age.
Those Celestial Bodies 