You certainly can include child object data in a field editor.  The only down side is that they are not editable.  We usually find that people want to edit the child data, and so they build a separate model (that is related to the parent) and include a second field editor.   The layout can get a bit tricky there though… 

Having said that.  If you want to include the child data in a field editor you totally can.  

1. Make sure you include the child data in your model 
2. Drag the child data item from the model field list into your field editor
3. Use the field picker to configure the data shown in the template field.

Hope you are successful. 

Jacob, Your approach should work just fine. The reason your Field Editor isn’t showing up, though, is that you need to go into your Child model’s “Advanced” properties, and check the “Create Default Row in Model” checkbox. This will make it so that when your page loads, your Child model will start out with a new record in it, that the Field Editor will show. If your Child Model has no records in it, then the Field Editor won’t show up at all.

Clarification point: Rob is talking about “Child Relationship” data, which is different than what Jacob is talking about. Jacob has a separate Model for his Child object data.

OK Cool, The trick for me was the “Create Row if none in Model” option. Jacob