Milkies
What my 5- and 7-year old daughters call breasts.  They witnessed their little twin brothers breastfeed, and therefore have no doubt as to the function of mammary glands on a human.
Mommy, look -- my dolly is having some of my milkies.  (her shirt is up and the doll is "nursing.")

This is not "sick" -- it is a healthy thing that the daughters are learning what to do when they have a baby.