When Peggy is shouting sexual body parts in the mirror at one point she shouts, "Uvula!" The uvula is actually the thing that hangs down in the back of the throat and is obviously not used in the reproductive process. She was saying "uvula" to work up the courage to say "uterus," much like she was saying "happiness" to work up the courage to say "penis" a few moments earlier.
Peggy tells Luanne that she "didn't even kiss a boy until I was 20" but in later episodes it's established that Peggy and Hank were high school sweethearts, who were depicted kissing.