"Will ISKCON accept people this young?"

Oh, yes, we, younger, even younger. Even one child is within the womb of his mother, we can teach. It is so nice thing. The instance is Prahlada Maharaja. Prahlada Maharaja, when he was in his womb of his mother, one saintly sage taught his mother about Krsna consciousness, and the child became Krsna conscious from the womb of his mother. So we can teach even in the womb of the mother because it is spiritual; it is not material. No material condition can check this teaching. Ahaituky apratihata [SB 1.2.6].

That is the highest perfectional system of religion, which is unchecked and develops love of Godhead. That is first-class religion, not under any condition. Ahaituky apratihata. Apratihata means without being checked.

Krsna consciousness is not such thing that because one is child, he cannot learn; because one is blind, he cannot learn; because one is poor, therefore he cannot... Because one is rich... No condition. Anyone, simply he must be a living entity, that's all. He must not be a dead stone. If he has got life, he can learn Krsna consciousness. It is so simple and so nice.