Basically the title.

In IW he calls Gamora the "daughter of Thanos" who obviously isn't her biological father, presumably just because she spent more time being raised by Thanos than by her biological father.

But then in Endgame when Clint and Nat go to Vormir he calls her "daughter of Ivan" even though she never even knew her biological father's name and would have thus spent more time with Alexei growing up (albeit still not much time, but at least she remembers him).

Why so inconsistent?
How did Red Skull determine who someone's parent was on Vormir?