Maybe she died in another county or nearby state and her body was brought back to Archbold for burial.Possibly visiting another family member?Have you checked for an obituary that may give information about where she died? Mary does not show in 1900 census in Fulton County unless she remarried and is listed with a different last name? Also find Henry Williams living in home of other with no Mary but he is listed as married??You find Mary in 1880 living with her daughter in Lucas Co. Ohio marked as widowed but this must be error as Henry did not pass till 1884. There is a Mary Williams of the right age still in Lucas Co. OH living by herself in 1900 and if this is your Mary she probably died in Lucas Co. OHIO
========================================= 1880 United States Federal Census about Mary Williams Name: Mary Williams Home in 1880: Toledo, Lucas, Ohio Age: 54 Estimated Birth Year: abt 1826 Birthplace: Ohio Relation to Head of Household: Mother-in-law Father's birthplace: Ohio Mother's birthplace: Ohio Neighbors: View others on page Marital Status: Widowed Race: White Gender: Female
Household Members: Name Age Daniel Monteith 22 Jennie Monteith 24(Jemima nee Williams) Libbie Monteith 2 Wm. Voltz 35 Edward Rotz 22 Mary Williams 54
=================================== Ohio Death Cert of Mary's daughter>
Name: Jermima Williams Monteith Death date: 16 Jul 1936 Death place: Toledo, Lucas, Ohio Birth date: 06 Jan 1850 Birth place: Archbold, Ohio Age at death: 86 years 6 months 10 days Gender: Female Marital status: Widowed Race or color: Caucasian Street address: 1334 Almon Dr. Occupation: At Home Burial date: 18 Jul 1936 Burial place: Archbold, Ohio Spouse name: Daniel T. Monteith Father name: Henry Williams Father birth place: Williamsburgh, Ohio Mother name: Mary Robinson Mother birth place: Reading, Pa.
GSU film number: 2022686 Digital GS number: 4041682 Image number: 3150 Reference number: fn 46298 Collection: Ohio Deaths 1908-1953
================================= 1900 United States Federal Census
Name: Mary Williams Home in 1900: Toledo Ward 15, Lucas, Ohio Age: 76 Birth Date: Jul 1823 Birthplace: Ohio Race: White Ethnicity: American Relationship to head-of-house: Head Father's Birthplace: Pennsylvania Mother's Birthplace: Pennsylvania Mother: How many children: 1 Marriage Year: 1896? Marital Status: Widowed Years Married: 4?Possibly remarried and then took Williams name back Residence : Toledo City, Lucas, Ohio