Looking for emigrant Susan B. Nelson

According to a history compiled for my family, this person was born in Norway about 1848 and emigrated with her family from Christiania to the USA at age 11. Wonder whether she appears on any passenger list. Digitalarkivet emigrantar records don't go back that early. I believe I have found her in the 1870 census in Janesville, Wisconsin. In 1872 in Wisconsin she married Hans Christian Tweedt, my great-grandfather's brother.