Found your great grandparents in the1880 census. It was taken about a month before your grandmother was born so she is not on it. But it does list Thomas E. and George B. as other children of George Dillon. They are on the third page of Chicago Juction-New Haven, Huron County, Ohio 1880 Census. The 1890 census was mostly destroyed by fire. The next one doesn't list her but she could be married at that time. Jessie Deith