Hello Doug,
My suggestion is to review the Overview article of the Kendo UI HierarchicalDataSource. It shows what data should be returned when child data is requested. The article does have a sample code that shows how to define a different data source for the child items.
Regards,
Boyan Dimitrov
Telerik
Join us on our journey to create the world's most complete HTML 5 UI Framework - download Kendo UI now!