Romanov was a child in Uncanny X-Men 268.
Marvel claims that Natasha and Scarlet share a birthday: November 22, 1984, even though Natasha claims to have worked for the KGB which shut it's doors in November 1991, which means that they were employing a tiny child to do something sketchy.
Marvel's sliding timescale has created a number of oddities. Probably partly why they're going the DC route of some universe smashing reboot to set everything back to zero. That said, isn't that pretty much the point of the Ultimate books?
Personally, I'd be interesting to see them make a universe where the timeline didn't slide and you have a modern day Cap who's been unfrozen since the 60's (and still barely showing his age) an old retired Spidey etc. and several generations of legacy heroes that have taken the place of their older counterparts. I gather that was (is?) a Spider-Girl book that took sort of that tac, but I'd like to see that applied universe-wide and give a much broader sense of collective history.
Pretty much how Dredd has aged in real time since his first book was published and over the years you've seen other judges come up from rookies (or babies in the case of Beany and some of the other Fargo clones) all the way up to veteran street Judges and in the case of Hershey, even a Chief Judge.