What's the plural of "Madonna and Child"?

I was wondering about this last Thursday, as I was walking through the Bode Museum. State-run museums are free from 6 to 10 p.m. on Thursday evenings here, so if you're cheap and here for a while, as I am, you can plan your visits carefully, not pay a thing, and have the thrill of being in a museum after hours.

Anyway, I was walking through a hallway of medieval art and wondering how many representations of the Madonna and Child I've seen. Madonnas and Children? Madonna and Childs?

Let's not even get into the question of whether it's Jesus's mother or Jesus'.