Daniel,
It might be your grandmother was the widow of John Thompson when she married your grandfather:
Name: John Thompson
Event Type: Marriage
Event Date: 18 Feb 1903
Event Place: Seneca, Nemaha, Kansas, United States
Gender: Male
Age: 39
Marital Status: Married
Race: White
Birth Year (Estimated): 1864
Birthplace: U. S.
Father's Name: Eli Thompson
Mother's Name: Catherine Lane
Spouse's Name: Loletia Maude Richmond
Spouse's Gender: Female
Spouse's Age: 19
Spouse's Race: White
Spouse's Birth Year (Estimated): 1884
Spouse's Birthplace: U. S.
Spouse's Father's Name: I. C. Richmond
Spouse's Mother's Name: Mary Parmon
GS Film Number: 1955334
Digital Folder Number: 007580100
Image Number: 00772
Citing this Record:
"Kansas, Marriages, 1811-1911," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:FWLR-VRD : 28 January 2016), John Thompson and Loletia Maude Richmond, Seneca, Nemaha, Kansas, United States; citing Marriage, 18 Feb 1903, Seneca, Nemaha, Kansas, United States, district clerk, county clerk and register offices from various counties. Kansas State Historical Society. ; FHL microfilm 1,955,334