My dd is 1 and so far we havnt had to really talk about her bits but she also is learning a second language. so far she knows most body parts/clothing in that language more so than English. Eg if I say to her where's your shoes? She has no idea but if I say it in different language she will point and look down at her shoes. If I have said anything about her vagina I say it in our language like in the bath 'stand up mummy needs to wash your etc etc' i guess once she's older I'll most probably say vagina although not too sure how much detail ill need to mention ie vulva/labia. Probably leave that up to the sex Ed chat.