I am researching the Edward Pyburn branch as well. His daughter Melissa/Milla was one of the eight children who were orphaned on the Oregon trail when Edward died of cholera. Melissa married Moses Preston Rice. Their last child, a male without a name on the 1880 census, may be my great grandfather Edward Rice.
It surprises me that an account of this difficult chapter for the Pyburn children was never written. James Shelton Hines was part of that wagon train, and looked after them after their arrival in Oregon. James later married one of the girls, Salina Pyburn.