True, definitely could do something along those lines. Would probably depend in-part on whether she thought she'd be able to get home/when she'd be able to get home. I think if Petra's interest in the language was an extension of her scholastic nature instead of necessity we'd have seen her clean up her trouble during timeskip.
Actually, looking at things more closely again, it looks like her battle/level/etc quotes do become more correct post-timeskip, but they didn't account for it in her supports that require being post-timeskip. That's annoying.
Like, there's a quote that goes from 'This is a way for getting more power' to 'This is a way to get more power,' and all three of her selection quotes improve post-timeskip.