"that's gross, I wish I were a boy"

Emma is growing up way too fast for me. I think being the oldest of 4 has naturally led her into questioning things about babies and bodies and how they work and recently the questions from her have gotten more precise and require a real answer about how it all works. Not too long ago we had the discussion with Emma about how babies get out of mommy's tummy. I told her some mommies have a surgery called a c-section where they cut into the mommy's tummy and take the baby out that way, and some mommies have the baby come out their vagina. She looked appalled that that can happen to your girly parts. She asked how it fit, and I told here when she grows up it would be able to stretch so the baby would fit, and then it would go back to how it was before. She doesn't need to know it's really never the same down there. And she was really just worried that after having a baby you'd be walking around with a giant vagina suddenly. That discussion was enough for her to proclaim at the ripe old age of 6 she was not EVER having a baby. She's actually stuck with that statement since.
I did think to tell her that these things we talk about are not to be discussed at school. Not because they are bad things, or there is anything wrong with talking about it, but because some kids' parents don't want them to know about this stuff yet, and they would not be happy if their kid came home saying they learned it from you. She said, "Ok, it's inappropriate for school. That's what we say when there are things that are not ok for school; inappropriate."
But I think the more traumatic discussion happened today after she got home from school. I was folding laundry (as always), and some of my cloth pads were in the pile so as I was folding one, she asked, "What's that?" I told her it's something that mommies have to use, thinking that would be the end of it since that is what I told her before and that was good enough, but that was not the case today. "Why do mommy's have to use that?" She asked. So I told her it was because mommies bleed and need that... "So it doesn't get all over you clothes." She finished. "Yes, that's right Emma." "Oh, where do you bleed from?" I stood there for a minute trying to figure out a way to tell her without scaring her to death, when I realized she needed the truth, and even if she didn't understand it completely right now, she could handle it. "Okay," I said. "I'm going to tell you something but I don't want you to be scared. When girls grow up they have what's called a period every month..." I then went on to describe what a period was and told her where the blood comes out. She wanted to know why it happens and I tried to give her the simplest version of it, but I think I lost her somewhere between eggs so small you can't see them, and the uterus. So I told her "I know you don't understand all this now, but you will as you get older and learn more about your body, and when you have more questions, just come ask me." So when we made it through all that, she gave me the most disgusted face ever and said, "THAT'S GROSS! I wish I were a boy."