It is possible the warts are not related to the swelling at all but just happened to be there when you noticed the swelling. Generally speaking, warts are only anti-aesthetic but not much to be worried about health-wise.
She might have stood on her teat when getting up from the ground, in which case it should go back to normal soon.
If the area (teat and quarter included) increases in size, becomes hard, sore and very warm to the touch then you should worry and call the vet (unless you already have some antibiotic that would cover for mastitis bacteria), but otherwise it should go away by itself.
As usual, keep an eye on it and see how she does!