Oh please are your pants not just any old judge incrusted knickers but M&S finest?
I too could be the person you are talking about, because I had my first young, and if he decided to have a child now, I would be,
DS is at a top uni, getting firsts, as did I,
Out of my friends that did the same, had children before 20, all of us have degrees great jobs, and all of our children are extremely high achievers, all uni educated, and going onto great things,
a very dear friend, who had three before 20 been with her husband for over 24 years,also (get ready to pull up those baggy knickers) bought her children up on the road(horse drawn,no benefits), has a medical degree, first child got a first, now still in education and won a much coveted award far younger than anyone before her, next sister doing a PHD education, next child doing a music degree in the best institute, next child has just won a music scholarship to a well known music school,
all of my friends who had children before twenty, have never regretted it, some have done both, had children in their thirties, it's far easier on your body doing it early, and none of those children have missed out on anything.
I watch friends in their thirties and forties struggle to start families, the lucky ones that manage it,often admit how hard they find the adjustment, from suit yourself adult to having to alter your lifestyle radically, the've watch us parent for several decades, and wonder why they find it so hard,
I must admit, that if I had been suiting myself for 10 to 15 years before having children I would of struggled, but as we did early, I found the baby and small child bit undemanding, if I hadn't had a second batch I would now have an empty nest, as quite a few friends do, lots off on adult gap years.
I think the hateful condemnation of younger mothers is spiteful, and dangerous.