How can we keep my child from depending entirely on a "friend who takes care of them"?

A relationship where a kind child always plays the caretaker, if it continues, robs your child of chances for independence and also burdens the other child. What we want to aim for is a relationship where "helping and being helped" isn't fixed. Try talking with the teacher about creating situations where your child can have a role or something they're good at (handing out materials, being the model for a dance) and about having support come from adults and systems (step charts, visual supports) rather than one particular child. The experience of "doing for others," not just "having things done for them," nurtures equal friendships.