Who are you to judge

I keep hearing 18-20 is to young to have a child. Who are you to judge when the perfect age is of having a child. Now obviously I don't believe in under 18 because they are students in high school. But I'm talking about those mothers who have finished a short career by 20 and have a good financial situation and decide to have a baby. People act like age is the time when in reality financial stability is the time that says when it's good to have a baby.