at 18months DD knows:

hair,
eyes, which she takes delight in poking mine 50times a day to let me know she knows
nose,
mouth,
teeth,
tongue, have to poke it out and wiggle it to demonstrate
chin,
cheek,
eyebrow,
shoulders,
boobies,
hands,
fingers,
tummy,
bottom,
feet,
toes.
No discussion yet on vulva/vagina although she did take an interest in mine in the shower, most unexpectedly - gave me a fright whilst bending over to wash my feet!!!!! LOL. Not sure what DH has called his bits when she discovered them in the bath (LOL!!). Will have to ask him.

She can only actually say, eyes, nose, mouth, hair.