How, exactly, are they working more? How many low-paying jobs offer overtime, if they are full time at all? Any clue how many jobs won't let you work a part-time job or won't work around another job? Can't exactly work for Uber if you can't afford a decent enough car. And this is assuming you have older children that don't need childcare.

The fact is that they aren't working extra, not for a job anyway. The extra work comes in the time making dried beans instead of buying canned, in repairing stuff poorly, in shopping around for a doctor that takes the state health insurance or an affordable option if you have none at all, in taking busses (if they are available), and other unpaid things. Your child will be lucky to afford the activities that gets them a 'good' education, especially if they have to work.