Found an unlisted sibling or child of William C and Petronellie Grant

I found a 1907 Indian census for Belcourt that listed a son named Lawrence. He was two at the time and listed immediately after Alfred. He must have died as a child. As I found him in an earlier census but not later. Lawrence was also found in the 1905 and 1906, but not in 1908. No death certificate was found on the North Dakota index of death from 1907. That site notes that most counties did not fully comply in registering deaths until 1924.