Amanda Bradford

I am looking for Amanda Bradford. Her parents were James and Martha. She was born in 1864, Van Wert County. She is in the 1870 census with her parents,sister Sylvia and brother Enos. In 1880 the family has moved to Union Township, Mercer County, Ohio. The father has died and there is no Amanda. I have looked for a marriage and can not find one. I can not find a death either. I would appreciate any help.
Thank you. Donna