We just had a discussion about this in our buddies group. I am a bit hesitant to use Vagina because it sounds so grown up for little kids, but that is my hang up not theirs and if i were to use it they wouldn't think anything of it. We use doodle for penis. So I am going for it, it will be Vagina around here.

I wouldn't entirely agree about using the correct names preventing abuse. I certainly knew what things were called and it made no difference.