A ferret and cat together as pets? please advice?

my mother is getting my son a ferret. We already have a 2 month old kitten that will be 3 or 4 months when the baby ferret comes. Will they get along? (since when they will be introduced both will still be young) will the ferret follow the cats example a use the bathroom in the same litter box when out ( if so I will change the cat's litter to a safer one for the ferret) I know the ferret will eat his food too. I been so long since I had both (when i was a kid) i don't quite remember. My mom said our old ferrets used the litter box with the cats and they got along. Could someone give me a update.