Ooooh, I like this development. The fight was great to witness and her reasoning as to why she's desperately wanting to duel with him is not something shallow either
Actually, as her (nominal) swordsmanship instructor I think it would be fair to say that his only duty is making her stronger, no? Since the bodyguard thing is a secret and all.
I would have liked to see him beat her ass, God I hate characters like her in every single one of the other stories I've read. Same story told over and over again with this knight princess chick.