I agree with Brillo, just stop doing her stuff. No clean clothes, no food, she'll soon get fed up of that. I wouldn't not clean the cats out as that's not fair on them, and I wouldn't want to live in a craphole either so I'd still be cleaning.
It's a bit awkward since you've got kids, but you could take all the plates and cutlery away (lock them round a mate's house or in a box at work or whatever) apart from one set for you and the kids. That way, you only ever wash up what is yours and theirs, and she will have to have paper plates and plastic cups and cutlery. That would get tiring for her really fast...