I know there's got to be a way to access this property, but it's driving me crazy that I can't find it!
The answer was NOT a footer -- but it was a "new row" so make sure to turn off allownew property if you don't want o have that extra row showing up!
That is how do I remove the summary row from child rows? This DOESN'T work:
grid.DisplayLayout.Bands["ChildBand"].Override.AllowRowSummaries = AllowRowSummaries.False;