Sophia Berntine Kvittem

I am looking for information regarding my Grandmother, Sophia Berntine Kvittem. I am not sure of the spelling of her last name. She was born in Norway on August 7, 1891, traveled to USA when she was about 17 years old and lived as a housekeeper in Sisseton, South Dakota. She latered married my Grandfather, Oscar Jamesgaard, lived in Minneapolis, Minnesota where they had two sons, Alvin and Donald. I am beginning my search for the place of her birth, other family members, when she came to America, etc. Any help you could give me would be greatly appreciated. Thank you!