- doubting that post talking about how were mostly stardust (if anything it undersells how much were stardust)
- black widow lore that I can actually answer despite not being into comics for very long.
So in cap 3 there was the part where they found Zola and he said that Natasha was born in like 1984 or something but like since nat was kinda like Steve wasn’t she born like decades before?
if by cap 3 you mean the second captain America movie (the winter soldier).
then the answer is both. it’s one of the diffrences between the movie universe and the comic universe, in the comics she’s a lot older than she looks and the serum she received slows her aging to a near stop. in the movies she hasn’t been active nearly as long.