Hi, That was a volunteer who helped you - not related. I also am not related. I noticed that you wondered about Mette's middle name. It may be that her death is recorded at West Moe Lutheran Church in Moe Township, Douglas County, Minnesota and maybe some volunteer there would look it up, it you write to them. The church can also probably tell you if the Hammer family members are buried in the church cemetery. The family was active in this church. http://www.dchsmn.org/places/churches/
Do you know of the website called Find a Grave? It may be that a volunteer with Find a Grave will be willing to go to West Moe Lutheran Church Cemetery and find Mette's grave. Again, I do not know but we can guess she is buried there.