I think I see the dilemma. You created the FAG memorial and now you want to verify that she's really buried there.
Finding old burial or burial transfer permits is next to impossible. There generally is no law that requires cemeteries keep them.
You can contact the Webster County Genealogical Society, http://wcgsiowa.org/
and the Webster County Historical Society, http://billgibbs.net/history/index.html
and ask if they have burial records or if they have inventoried the cemeteries in Webster County.
If she was buried without a tombstone, you might not be able to verify where she is buried. Successful Searching!