I'm not sure what she used to detangle, but the best way to do it is when the hair is wet with conditioner (she can also add EVOO for more slip) and a wide tooth comb or denman brush. Splitting the hair in sections will help too.
Here are some helpful sites that you could pass along to her to look at
Chocolate Hair / Vanilla Care
Beads, Braids, & Beyond
Happy Girl Hair: Natural Haircare for Kids