My ggggrandfather was Elias Wallen who died in Butler County, Ohio in 1805. His wife was indeed Mary Kerby. Seven years after Elias' death, she married Thomas Fream, a Cincinnati tailor (in 1812) and moved to Monticello, Mississippi. She and Elias had two children, Alexander J. and Jane. Jane went with her mother and new husband to Mississippi, while son, Alexander, settled in Canada.
Alexander married Margaret Boyle (1826?). They were married for thirty years. They had eleven children but many did not survive beyond childhood, including a son, Elias. My great-great grandfather was their sixth child, John, born in 1833. I have no information regarding any other Elias Wallen.