I replied w/ "nothing. Why do you hate to ask?" and W's reply was: because I don't like you or trust you any more -- yesterday didn't help.
Answer; " I don't trust you either after all the lies you told about me yesterday."
You're a saint, really - but be careful here, I know she's whacked but she could also screw you over big time if you're not careful.
As for the head lice - she's probably not getting re-infected, it's just hard to clear all the lice from her head. It's much more likely that one louse survived the treatment and laid more eggs, than that she picked up another louse from the apartment.
It just takes persistence. Fumigating the apartment was probably unnecessary in the first place, repeating it is probably worthless.