Copied this from another user: ( SPOILERS!! )
- She was 21 and he was 24 when they married. She was 19 when she was summoned, just before her college entrance exam, that’s why she was in uniform.
Like what a previous post said, their time flows differently. Anna spent years at Lohengrin but her time resumed like nothing happened when she went back to her world. She literally came back at the same time she was transported. That’s why she doesn’t remember anything, and why she became a virgin again. It’s like her time in Roth’s world never even happened. The years spent in the other world was just like a blink of an eye in Anna’s world.

Why was she in school uniform in the flashback? EYUCK!!!! dropped ngl I have my limits