My in-laws were shocked today to overhear my 3yo saying she was just wiping her vulva after she'd been for a wee. They think it's wrong for her to call it that and she should use a more "child friendly" word (tuppence was grandma's suggestion). Now my husband has said that he actually agrees with them and he doesn't think it sounds right her saying vulva.
Background info, I'm a survivor of childhood abuse and, although it wouldn't have made any difference what I'd called anyone's genitals, I think that's had an impact on me wanting my children to know and use the right words for them.
So, YABU - she should use a more "child friendly" word.
YANBU - it's good for her to use the correct name.