Would you want that on Facebook

I was on Facebook and my husband's BM made a post about their daughter(14) getting her first period and how she's a late bloomer. Now I'm not going to say anything to her but I'm just like "Why would you put that on Facebook. Her daughter is on Facebook and she will probably be mortified. Maybe I'm missing something because I don't gave kids? Is the first daughter getting her first period a very big moment? I still wouldn't share it on Facebook but maybe I'm missing something.