Anton A. Hagen (1867-1948) and Emma S. Hagen (1862-1948) are buried in Riverside Cemetery in Black River Falls (section 11 Row 15 #5) along with Gilbert A Hagen (1897-1962) and Edna Hagen (1904-1966). But I do not see a record for Marli/Mali/Mari Hagen. I also checked cemetery records for Little Norway Lutheran church near Black River Falls, but I could not find it there either.
She is not listed in the 1900 census records for Jackson County.
There are many Hagens in Black River Falls - originally from Ringebu and Lillehammer area. Your line does not seem to be related to any of mine.