Try the Garson cemetery. Although there is no headstone for her there there are a number of related Halversons buried in the older section of the cemetery which may suggest that an early burial took place.
http://freepages.genealogy.rootsweb.ancestry.com/~murrayp/su...Her Ontario death record indicates that she died of colon and liver cancer and that an operation occurred about two months before death. It does list Leclair as the undertaker.