When introducing new animals to cats, it is best if there is a closed door in between them for days. You can try making sure the cats have a safe area that is a no dog zone and vice versa. Also, try wiping them all with the same scented, pet safe baby wipes so that Mia smells "right" to them. If Mia has a wire crate, make sure the top is covered so cats can't swing at her. It takes a while.