I can tell you a flea collar will not work and I wouldn't suggest this at all considering she is nursing.

Sorry but I want to make sure this is the right kitty. This is the same kitty that had babies by c-section? I know the cats name was Snow but I cannot recall if was your Snow or another member. For some reason I am thinking it is another members kitty. Sorry if I got her mixed up with the other.

If this is the same kitty that just had babies then I would suggest calling your vet to find out what is ok to use while she is still nursing them.

Sorry for the confusion.