Who is Mother from What Have You Lost? and what is their importance?

The author's mother stares impassively from the picnic table, opposite of the side where her husband serves potato salad. Her high cheekbones and straight black hair make the author think she could be Tecumseh's sister. The pitch of Mother's voice frightens her daughter who still wants to vanish into the woods with her. The author believes Mother could have been Tecumseh's great-granddaughter, and they could have been happy.