Year 2 teacher...we teach (and use) the correct terms in school OP, but from first hand experience and 28 years teaching primary, I can honestly say that, despite popular MN rhetoric, I rarely have more than one or two 7 year olds who know these real terms!
I can also categorically myth-bust the other old MN chestnut, that 'if you don't teach the real terms, how will anyone know what your child is talking about if they ever have to disclose an issue'...we do know what they are talking about!! Context is everything 🤷♀️ Minnie, flower, tuppence, foof, foo, Mary, widge, bits, front bottom, woowoo (that one made me laugh 😆)...sooooooo many names 🤦♀️🤣
Of course we'd rather they come in armed with the correct vocabulary, but having your own family name too is no bad thing I don't think (as long as they do know that 'the real word is x, but at home we can say y if we want to!)