I have also wondered about the statement that Rachel Alderson was Joseph Smith's sister because I am researching Joseph Smith's family. What if Rachel Cole Alderson was Joseph's sister-in-law? I know that Joseph's wife was named Sarah. There is a website called "Descendants of James Cole" (don't know how reliable), but it lists the children of James Cole and Averliler Daniel as Sarah Cole b. 1744, Rachel m. Jeremiah Alderson, Josiah Cole m. Elizabeth Moore among others. Mary Whitworth Cole daughter of Josiah and Eliz. Moore married Joseph Smith's son Robert. We know that there was a lot of intermarriage between a few families in those days.