I had no real plans for the slaves. They are like the equivalent of 10, well behaved and she treats them like dogs. Not badly, just like they aren't real people. They are to do what she commands and melt into the background when she doesn't want to deal with them.
Not sure how much fun they would be. She doesn't want firey slaves that need to be broken in or anything. But if you want too play one, there is a boy and a girl.