Lkg for Bertha Torkildson/Lars Modahl

I am attempting to research information on my husband's grandma, Nettie (Modahl) Olson. Her mother's name was Bertha Torkildson and father was Lars Modahl. Married Carl A. Olson in 1916 in Sheridan Cty Montana. She is buried in Pelican Rapids MN, I think. She said she came over on a ship when she was about 14 yrs old.