Did Carol forget she was older than her brother Joe Danvers (and other brother Steve Danvers) or did the birth order get Secret Wars retconned?
(Ms. Marvel volume 2 implies Steve is older than Carol and that Carol joined the air force after Steve was killed and she turned 18. But I'm pretty sure that's not true and that Carol was the eldest sibling in Ms. Marvel volume 1 issue #19)
It is sort of easy to infer Carol was the oldest from Ms. Marvel #19, but not necessarily. She was 17 when we see that argument between her and her dad. When he says only Steve will go to college, it really doesn't have any bearing on their relative ages.