I only have a little more to offer you. Not too much has been discovered by me. I cannot help you with Sarah's family EDWARDS. Have nothing. Strange that they were in the 1880 CA census but children in school in MO. What's that all about?
Question: Sarah's parents were supposedly married 1836 -Where? No children for six years until Sarah 1842??
Siblings of Sarah Ish: Angelina was not included in this household 1870 CA census, Yount Twp., Napa Co. I have nothing more on here. James was in the 1870 census, age 21 living with parents You have Jacob E. (Edmund), 1870 census, age 19. Milton C. 1870 census, age 17 John W. 1870 census, age 16. Married Jennie Rosa Gable born 1861 CA; This couple was in Winters, Yolo Co. 1880 census: 2 children - Lilly b. ca 1878 and Harry b. ca 1879. I have no further details on them. Mary 1870 census, age 16 (twin to John?) Frank (your F.W.) 1870 census age 14 Fannie 1870 census age 11 Arthur B. 1870 census age 10. 1880 census Spring Valley, Colusa Co., CA; married Nellie WOLFSKILL. 1900 Census CA in Winters, Yolo Co. Children: Margaret M. 1890, Carroll Wolfskill 1891, Dorothy W. 1892, Leila 1893, and Arthur Buell 1896 marr. Gladys Brinck. 1880 CA census Winters, Yolo Co. Carrol Ish age 65 Mary Jane Ish age 63 Fannie L. Ish, age 22, sing. dau
CA Death Records online has a John EDWARDS b. 7/9/1871 died Orange Co. 7/15/1946, age 76. (The birth yr. would agree with your Jr.)