From Folldal, Hedmark to LaCrosse Wisconsin

I am looking for decendants of my great-grandmother¨s sister Marit born December 27 in 1842 and brother Petter born April 16 1867. They were children of Ole Erlandson, born October May 14 in 1819 and Marit Pedersdatter Stadsbyøyen born September 26 1821. Marit emigrated in 1868 and Petter in 1888. Any infomation is welcome. Bente