I had the convo with DD who is 8 (9 in a few months) because she is starting puberty.

I bought her a puberty book to help understand a little more and it explains things in a little more detail.

She had LOADS of questions which I answered honestly for her we've had the period talk from quite a young age (around 4ish) because she asked me in the pad aisle why I was buying nappies for myself