Thank you for looking! I also had no luck on searching the censuses.
Lettie May (Roberts) Larson was my grandmother's sister.
My grandmother was Martha EMMA (Roberts) Lindsey.
I believe both families were active LDS members. The children of Emma and my grandfather, Kingsley Claude Lindsey, were 4: Lamar (b. 1921), Don (b. 1925), Mary Josephine (b. 1928) and Janet Rae (b. 1934). After the eldest, the other three children were born in Pocatello.
They also lived near their cousins Roberts in Pocatello (children of Eldon and Marie Roberts. Eldon Roberts was my grandmother Emma's twin brother.)
It's amazing that they were all so close at the time but I don't have a way to show the connections now!