Not all kids have the same interests, or families. My parents never taught me to cook- so I didn't learn until I was in college.
If you don't know even the basics, just boiling water to make Mac n Cheese is a daunting, alien cliff.
Plus, some of Rekeita's kids are around 3-6. If parents aren't feeding them or keeping snacks available, they cannot feed themselves. That's either complete neglect , or just kids taking advantage of someone being in the house often enough to be familiar. (Why the fuck is this weird asshole familiar enough to these kids for them to beg him for food?)