Is it an old save (v8-10)? Start a new game, the code has changed a lot since then and you have to start over.
Not an old save? Start a new game, there is no fix for that (nor will there be).
I would appreciate details of how you broke that. If it was by gifts, you shouldn't have over-leveled the girl as you broke your game yourself. Although I find it odd that it was because of gifts since it's "technically" impossible for that to happen since many versions ago.