hahaha the dreaded question. ¡¡¡¡OMG!!!!
When my oldest daughter asked that question, I was clear and direct at the same time. The mom started to tell me that I was crazy for explaining all that to her, but with me they were also very direct when they explained it to me hahaha. the same thing happened with my second daughter, I explained it to her as soon as she asked me. It is true that at the beginning you are left wondering what we are going to answer, but I preferred to go straight to the point.
As a child I remember being told that if the mother took a pink pill she would have a girl and if it was blue, then the baby would be a boy. That instilled in me a terror of taking pills, and if I had to, I would ask to see the color first. Innocence...
With my children I was clearer, speaking in terms they could understand and not giving details unless they asked for them.
I consider that this is the best thing to do, and that they also know that they can talk to me about any subject, without fear or taboo.