My own experience was particularly cringey so I always vowed my daughter would never feel the same levels of awkwardness as I did. My mum is rather twee and lovely - and told me about periods a few months before I started. She basically seemed very shy and embarrassed, gave them the pet name of "pyramids" 😯 and gave me some huge sanitary towels in a huge make up bag - so I could hide and disguise them in my school bag. I actually remember starting my periods on April Fools Day and telling my mum "I've started my pyramids" and then having to disguise the huge make up bag in another bag in my school bag. Even changing my sanitary towel at school was a mission and I would wait until there was no one in the toilet so I could then go through the rigmarole of the rustling and unzipping of the multi bags !
So, I have always been really open and cool to my twins boy and girl. If they asked what something was I told them - ie sanitary towels, contraceptive pill, why I shaved my arm pits.
In year 6, the twins had their official sex-ed class. I knew it was coming up so said we would chat further about it after school. Son came home happy and chatty - amused that he had touched a tampon and a condom. My daughter was mortified and handed me a Jacqueline Wilson-esque note (attached to this post) and scurried upstairs. Basically the thought of periods had become real and inevitable to her and the realities of a tampon horrified her. I decided not to push the issue and take her lead as she knew the facts (and had for some time) - she just had to come to terms with it all.
Shortly after, she started to grow underarm hair, which she wanted removed, and she also wanted to shave her legs. This allowed us to revisit the puberty subject, and she told me that some of her friends had started their periods and had shown her some sanitary towels in pretty wrappers. So we went out and bought some and she dedicated a drawer to her little collection.
I did find, that when she started secondary school - she became a lot more open and periods became a more "cool" thing.
She finally started a couple of months ago (shes nearly 13 and the last to start in her group of friends). She came downstairs and told me really matter of factly "Mum, I've started my periods...I've sorted myself out...I've got enough towels for school...now don't say anything embarrassing".
I guess some situations, however you broach them, are a little awkward -especially when they relate to you. Just after the sex ed, I had to announce to the twins I was pregnant which was met with "Ewwww...that means you've had sex twice !" , and "why weren't you taking those pills ?" So my daughter was fine about talking about issues that affected me, but flustered about the changed in her own body.
She will probably remember the sex education at school in the same way I remember the "pyramids" chat - and vow things will be different with her own daughters !