Marthe Aalseth is the daughter of Kristian Oscar Marendahl. She immigrated from Norway with her parents and family in 1859 and they settled in Wisconsin. She married John Aalseth in 1865 and together the couple moved to Dakota Territory by 1867. Her father, Kristian Oscar Marendahl changed the family surname from Marendahl to Peterson after coming to the US. Christianson is not her maiden name.