Why don't they just turn her into 1/2 cat.  This should help them out.  Or
at least plan to.
Mike

Johnathon and Kasumi did discuss Kasumi using the drowned girl water to become
a half-cat, just before they got married.  They decided to wait and think
about it further.  After Kasumi was cursed with the Cat's Tongue, Happosai
stole the drowned girl water.  Then accidently used all of it on Artemis and
Luna.  Therefore Kasumi can't become a half-cat without going to china and
visiting Jusenkyo again.  Not an easy undertaking...

I am thinking that Johnathon would be considering doing so.

Actually, Johnathon has considered it.  In Chapter 16 he and Kasumi discuss the
possibility.  Johnathon is afraid that if she becomes a half-cat, she'll be in
danger of getting hunted down as a monster.  If she's permanently stuck as a
half-cat, that danger is worse.  As long as there is a chance of getting the
phoenix pill, Johnathon is willing to wait.  In the end it is Kasumi's decision,
what she wants, Johnathon will go along with.