My main argument is that she _isn't_ like her brother.  Kodachi is
considerably more intellegent and (IMO) has a firmer grasp on reality that
Tatewaki.  If the curse is displayed/explained to her and she a) cared for
him in the first place (which has been disputed) and b) does not hold her
defeat against him, then the curse would be more of an amusement than a
problem.

	Both Kuno and Kodachi take very much after their father.  Oh and in the 
Cookie storyline in the Manga Ranma got turned female while Kodachi was holding 
him and she didn't realise about the curse.