Fertility has nothing to do with "maturity" you don't have to like it, but that's when women's fertility is at its peak. And the reason most 24 year olds today can't handle life frankly is because their parents didn't do a very good job raising them IMHO.
Personally it has no affect on me when a woman reaches her fertility peak I had a child at 22 and did not want anymore. As fas as parents not raising them right has nothing to do with how much it costs to live out on your own. All you can do is try your best with your kids and when they grow up they make there own decisions.
I had great parents but when I got a certain age I was gonna do what I wanted to do mistakes and all...