I have no connection to this family.Saw your query and did some searching. This is all I could find.Would suggesst you send for Elva's birth certificate to find out who her parents were.
1920 United States Federal Census about Elva E Shroyer Name: Elva E Shroyer Home in 1920: Sidney Ward 3, Shelby, Ohio Age: 6 years Estimated birth year: abt 1914 Birthplace: Ohio Relation to Head of House: Granddaughter Father's Birth Place: Ohio Mother's Birth Place: Indiana Marital Status: Single Race: White Sex: Female
Household Members: Name Age John W Gilmore 58, head, married, b. Ohio, parents b. Ohio, laborer, Susan G Gilmore 56, wife, Mongrat? ?? co. b. Indiana Nancy Shroyer 30, daughter, widow, b. Ind. ??? candy co. Ralph G Shroyer 60 , grandson Elva E Shroyer 6, granddaughter Ruth H Shroyer 4 5/12, granddaughter