How many bees for three frame medium mating nucs?

I'm starting to put medium frames of brood above queen excluders to use in my queen castles when my virgin queens arrive.

I'm concerned about over stocking / under stocking the mating nucs with bees.

My intention is to have mostly sealed brood with just a small amount of older larvae, a frame of honey and pollen, and a mostly empty frame possibly containing some nectar.

With that makeup, would the bees covering the prepared frames be adequate? I picture there being about two cups of bees...

How many nurse bees should a three frame medium mating nuc be stocked with?

MAteing nucs need about 2 cups worth of bees, more is fine but not needed. Less and she won't show a good pattern of laying as theree are no nurse bees to feed the larve.