Looking for great grandparents

My grandmother's name was Marie Fredrikke Rhode who was born in Norway on Nov. 22, 1874. She emigrated to US with her mother about 1869. Her father's name was Ingemar Ludvig Fredrik W. Rhode. Her mother's name was Anne or Anna Marge Pedersdatter. I'm not sure what part of Norway they were from but I have some unidentified pictures with a Christiana location stamped on them. I would like to find more information on Ingemar and Anna. My grandmother and her mother eventually ended up in North Dakota. Thank you for any help anyone can give me. [:)]