Hi Ginger, I didn't find Annie or Nettie or family.
Jack is a nickname for John like John Kennedy was called Jack. My Uncle's first name was John but everyone called him Jack.
I did find an 1870 Looking Glass, Douglas Co., OR Census where a Yarborough family is listed. R., head household, 51 yrs old, b. KY, farmer; Mary Ann, wife, b. IL, 38; John, b. OR and all rest of children born OR, 18; Mary, 15; Ruth, 13; Francis, 12, Douglas William, 10; Jefferson Davis 8; Solomon 5; Washington George 3 and Martha, 1.
I also found a 1900 Bully, Malheur, OR Census with the Hunter family and a Solomon and Nettie Yarbor. Solomon, b, OR, Nov. 1866, employee, marr 7/12ths month, farm laborer; Nettie, wife, b. OR, Jan 1885, boarder.
Annie and Jack could have died and their death info would be located in the County where they died (if their was official death info). If you know where they were married, I'd contact that County Clerk or Court House & ask if they have death info.
They might have lived in Malheur County where Solomon & Nettie lived. You could inquire with the Malheur County Historical Society, 589 SW Second St., Ontario, 97914. Hope this helps!