8 "Unanswered Questions" From Avengers: Endgame, Explained
6. What About Sharon Carter?
Yeah, this one's a little weird. But as we've established, Steve couldn't have lived with Peggy in the timeline that we know as the canon MCU timeline. So while it's a bit unsettling that Steve would be married to his old flame's great-aunt without either of them knowing because they're technically different people, he just had to take this one on the chin.
It's possible that Sharon Carter doesn't even exist in this alternate timeline. Steve would have had to go back to before she was born. Perhaps some small detail had a knock on effect on the life of Peggy's family to the point where Sharon was never born.
You have to kind of feel sorry for canon MCU timeline Sharon, though.