We always used the correct names for body parts, vulva, penis etc along with ears, nose, arm, but did use some "pet names" for bodily functions. Goodness knows why
We never said 'do you need to urinate', or 'empty your bladder', normally using 'do you need a wee' to very young children and 'go to the toilet first' for older ones with a 'just try' when the older ones insisted they didn't need to 'go' before a journey. Why wouldn't we ask a child if they needed to empty their bowel? Just conditioning I suppose, and the language seems too grown up and even 'medical', but that's just perception.
As for all the words for vulvas, that's just euphemisms gone mad! As a child all I knew that area as was 'privates' ?