I wanted to thank you again for all your help. The two sisters, Christine and Kirstine or Kjerstine were said to both go by Christine.
My uncle Bob is meeting with the grandson of the Christine in Idaho to compare genealogy later this month. I think it looks promising that you found the right one. For one thing, this Christine named her granddaughter Wangelsten, which is very close to her sister's middle name. Not very common. Also, one son had the middle name of Lemvig, which was her brother's middle name. I know Norwegian names are repeatedly used over and over, but I have a good feeling about this.
Thank you once again.