Hello from Skagway Alaska! Justina shows up on the 1900 census as an orphan living in the Peniel Mission. The history of the Peniel Missions is interesting, apparently Victorine Tooley or Yorba and her daughter(?) Roberta Yorba were members of the Peniel Mission in Sacramento and decided to establish a mission in Skagway and when they moved up, brought both Justina and another orphan, Gusta Carnahan with them.
The Peniel Missions were dedicated to helping the "soiled doves" or prostitutes. There is no record of any of them after 1900, so they may have found better areas to take the Mission (once the gold rush was over, the population of men and consequently prostitutes dropped). I guess that means that Justina was an orphan in Sacramento so her parents must have died before 1899, and they were all from Sacramento. There is a short book in the National Park Service library here that is about the Peniel Missions.