Car/Gas/Insurance (required by most jobs): $200/mo
Monthly bus pass $100
A (cheap) 2 bedroom apt: $900/mo
Get a roommate
Utilities (no longer included, thanks 2008 housing collapse :( ) : $200/mo
Step back to basic cable (or even broadcast TV) and drop the unlimited data phone plan. Never seen an apartment yet that split out HVAC by unit, and it's hard to spend that much heating/cooling a 2-BR, unless you leave the doors open all winter.
Health Care (with a kid): $400/mo
You're raising 2 kids on $27k: you qualify for Medicaid
Food / Toiletries (3 ppl): $600/mo (eating very poorly)
Number 1: if the best work you can get is minimum wage, maybe you should put off that second kid or ask your SO to help out with expenses. Number 2: $20/day will feed dad+2 kids pretty well, as long as he cooks. Seriously: that's 2 pounds of chicken + 2 pounds of rice + 4 pounds of carrots and a gallon of milk, with enough left over for salt, pepper and ketchup
If you're working 2 minimum wage jobs, you don't get the American Dream. You adjust your lifestyle. Those sacrifices will make your eventual success all the more sweet and motivate your kid(s) to rise above.
Any emergency (car [wreck], and the other guy drove off) and you're basically boned. I think I heard some economist call it a "Fragile Existence"
Yes, if you're living on the edge, then small calamities become disasters. One hopes those are the circumstances where your community (church, neighborhood, or government) pulls together and helps you through.