Hi G.....I know exactly what you're going through. I have five children ages 20, 19, 17, and 14 year old twins. Four of them are girls, and it has really irritated me that they are having to grow up so much faster than I did at their age. I don't think I knew exactly how things worked even when I got into high school....and I really didn't care to know because being a Christian I knew I wasn't doing anything before I was married, and I knew I figure it out at some point...lol... Anyway...my kids weren't all that inquisitive...thank goodness...but I knew it was coming, so I bought a set of books I had seen James Robinson recommend. It has all the different levels from what to tell very small children all the way up to teenagers. When they got to around 10 or 11, I gave them the first one and told them to read it and tell me if they had any questions. That kind of broke the ice and made sure I didn't approach parts of this subject that they weren't even wondering about. We've had a few talks and tried to make sure they know where the Bible stands on this subject. Our neice who is a few years older than them unfortunately gave them a great example of what not to do...she got pregnant her first year in college and ended up deciding to give the baby up for adoption. They saw the problems and emotional pain that she had to go through, so it was an excellent life lesson for them. I'm still not done of course, because I really haven't talked to my twins that much about it and I know they already know a bunch of stuff just from being in school and what they see on tv. I'm fixing to sit them down and have one of those embarrasing but necessary sex talks whether they think they know it all already or not, because it is totally scary the amount of sexually active girls and boys that are in our schools and with all the STD's that are out there, I've had to get over my irritation about them having to grow up too fast and just tell it like it is. I guess the best thing, if you're a believer, is to just pray about it and let the Holy Spirit direct you in what to say to her. He knows exactly what she's ready for and will give you the perfect words and time to say it.
God Bless....K.
P.S. These books were written by Bill Ameiss and Jane Graver. The series is called Learning About Sex, a series for the Christian family. The different books are titled:
Why Boys and Girls are Different, Where Do Babies Come From, How are you Changing, Sex and the New You, Love, Sex, and God, and How to Talk Confidently with your Child about Sex...and appreciate Your Own Sexuality Too. Hope that helps!