Knox, according to the interview with Heather Kelley's mother, she did work. Her mother stated that "she went to work" . . . as proof that she was a good mother, and did what she had to do. That's all I have to go on, though. So don't know for certain.
Also, as a second thought, when someone applies for assistance they are required to divulge who the other parent(s) is/are. The State will then pursue that/those individual(s) for financial support of the children. However, if the father has no income, you can't squeeze blood from a turnip. But, the amount owed is documented, with interest mounting -- so that when, and if, the father does have income, he won't escape what he owes ("Death and Taxes . . .).
In the interview with the paternal grandfather, it was stated that he was "estranged" from his son (the father of his eight grandchildren). It was also stated that the grandfather believed that the eight children were now living with estranged son. If that is the case, how could he be awarded custody of the children if he had no income?