Here is Margarita Brittain's (Britten) 1911 Selection for Allotment. It is interesting that it was signed by Mr. L. W. Green. This is the same alloting agent that on December 5th, 1910 noted that Margarita Brittain was full blood Cupa Indian.
1911 Margarita Britten Selection for Allotment (Brittain)