A childhood belief about rude bits

My mom always called a vagina a "wee wee" (or something of that nature). So, my younger sister had a friend over who had a much older sister, and they were talking about sex. They didnt know much (They were like 7!) but I heard the word 'vagina" coming out of the room they were in, and my sister ashed her friend what that meant, and she said a girls peepee. I thought she said Buhchina (like the country), so i was convinced thats what the medical term was. Later, I said to my mom "Mommy, why is China named after a bad thing?" She was confused, so I told her that a girl's vagina was called a Buhchina. She laughed and laughed. Then, she told me the story. What was more embarassing was the fact I was about 10.