She liked to remind young women that she had taken off only five days to deliver her three sons and advised her graduate students with what one thought of as Millie’s Quantum Theory of Babies: “You must have either two or four kids for a stable family life because kids are like electrons in an atomic orbital. They come with spin up and spin down, so you need to have a stable configuration. You can’t have one or three kids because that would be unstable.”
