Well, this flea bombing seems to have taken. Much much less fleas around now (there's always some). I gave Ebony the excelpet anti-flea thing but held off on Gabby. If she does have a thyroid condition (as suggested by one friend) I'd do better to take her to the vet and definitely shouldn't give her the anti-flea treatment.
Gabby is looking better today, but mostly sleeps on a cushionon the kitchen table. Bobby has stopped scratching as much as he used to, and Ebony is sleeping in a wardrobe.