Well, I got mine watching High Anxiety at the movie theater. When I got home I asked my mom if "this" is what I thought it was? She smiled, handed me some dollar bills and sent me to get pads at the local corner store. I wanted to die but at the same time I felt older. LOL My aunt on the other hand was on the other spectrum, she ran into the house at a family get together, grabbed me and planted a kiss on my cheek yelling "Your a woman now!" That time I really wanted to die.
I think you'll be fine. They teach so much in the school now regarding this and other stuff. The day my son told me he learned to out a condom on a banana I thought I'd fall over but I have regained my composure, better them than me to teach that! I handed Jim the condom and told him to give it to Chris for senior prom or I would. We're very open here at the house though, no shame in what is a natural thing in our lives. LOL
Sounds like your a great mom and she is lucky to have you.