So, the first person profiled in the story grew up poor and is now wealthy.
And the second person profiled has a lower middle class income and the attitude that "it's not possible to get ahead".
Anyone notice the irony in that?
The second person has two basic problems:
1) She is a single parent of two kids.
That's a simple statement of fact, it's not "slut shaming" or anything like that. I have no idea how she got into that situation. Having two kids (and wanting to raise them right) takes a significant amount of parental time and energy. That makes it triply hard to get ahead financially because of the time commitments and the extra expenses, especially daycare.
To turn this observation into actionable advice, (a) don't get pregnant or get someone pregnant unless it's the right time to have children for both of you, (b) have enough life insurance on each parent so the surviving parent and kids have enough, (c) only have children with people who are competent at daily living, kind, responsible, fair, honest, prudent, loving and reasonable. Even then things can go wrong, but there's no reason to stack the deck against yourself.
2) She doesn't think she can get ahead.
So she has not plan to do so. No plan to cut expenses. Get a roommate, move back in with parents, get work closer to parents so they can babysit and cut daycare costs. No plan to grow her skills. An hour a week spent reading about new skills and practicing them - which is totally do-able in an office environment at lunchtime - can pay real dividends over the course of a year. Finding MMM and reading the info here could change her perspective on life. Learning new, marketable skills could get her a promotion or raise, leading to even better positions in the future. Whether it takes 6 months or 36, it's progress. And as we all know, constant growth leads to compounding results.
Then there's the 3rd couple with 4 children. Had they stopped at 2 children (ages 10 and 8) the mother could be working at least part time. Depending on the kids, in a year or two the kids could be latch-key kids who come home from school while mom is at work. Daycare costs would then be zero. Instead, they had 2 more kids, thus starting the expensive day care or lost 2nd income problem all over again. And the expenses given don't add up. $1500 for rent and $1000 other expenses = $30,000 expenses on a $50,000 income.