Girl spends 3000 years training mostly alone. Instead of achieving enlightenment or going full castaway, she's self conscious of her breasts.
Wanting to write a setting where a lot of time passes is one thing but where characters' personalities don't change over the thousands of years they've been alive is going overboard, specially since the time frame could have been altered to no effect to the story and/or have them having spent most of it sleeping/in stasis/dead.