Elizabeth Glass Stafford is buried in Erie County, PA. Her Find-a-Grave entry says she is a daughter of Wm & Mary GLASS.
"Find A Grave Index," database, FamilySearch(https://familysearch.org/ark:/61903/1:1:Q29B-DBHF : accessed 27 April 2016), Elizabeth Stafford, 1857; Burial, Erie, Erie, Pennsylvania, United States of America, Erie Cemetery; citing record ID 151262292, Find a Grave, http://www.findagrave.com.
Hope this helps! -NGP