Interesting. But in that theoretical book about your life, just because a particular character is ignorant of something, doesn’t mean the reader can’t be shown what’s really going down.
Second, “it would be a realistic reason” doesn’t wash for Harry Potter. Very little of it is “Middle Ages” in a realistic sense. The world of He-Man is more “realistically” Middle Ages than the land of Harry Potter, in a lot of ways.
More simply:
She could’ve done more, but she didn’t, which is her prerogative for her own thing, but that means she’s not going to get full credit for doing something she didn’t fully do. (She can still have some credit for the parts she did.)
She can choose less, but that doesn’t mean she had to choose less.
