As a longtime lurker but relatively new registered account haver, I couldn't help but notice that when I go into "My Mumsnet" & click on "Account details" & the "About you" tab, it says:
Your children
Mumsnet offers regular emails on your children's development. If you'd like to receive regular emails on your child(ren)'s development, please record their details here.
Gender
Date of birth
I found this alarming & amusing at once, though not in equal measure.