TLIK: Divorcees with deadbeat dads should be in the same category as Almanos & Yesomim, as their father has “given them up”. The community to which the children belong should find them (and pay for) a school to go to, perhaps by working out a “bulk discount” for children of this type who need a school (If they have 20-30 children, the community Tzedaka can negotiate a significant discount & send all of those children there).
In that sort of situation, I would hope people would help. I would also hope divorcees & widows are the exception, not the rule.