Margaret and John Orr of Zanesville 1860-1880

I believe that Margaret's maiden name was Sheils and that she was born in County Roscommon, Ireland around 1830. She was mentioned in a biographical sketch of her younger brother John Sheils, a hotelier in Ulster County, NY published in 1896. There she was listed as married to John Orr (though spelled Awer, which I believe was incorrect), a foundryman in Ohio.

I think I found Margaret as Orr, age 30 born in Ireland, in the 1860 census in the Zanesville Ohio household of G.W. Graham 35 and  Rebecca 30 both born in Ohio. Her husband John is not with them, but there is a 16 year old Emma Orr born in Ohio. Who is she? Not likely to be Margaret's daughter. Perhaps she is a relative of John -- or even a daughter from an earlier marriage? How is Margaret affiliated with the Grahams? Where is her husband (I have not found him in 1860)?

The 1870 census in ward 6 of Zanesville shows John and Margaret together, he is 55 and she is 40. No sign of the Grahams nor of Emma Orr. Now with them are Agnes, 14 and Frank, 9 -- assumed children.  But where was Agnes in 1860 at age 4?

In 1880 Frank is living alone, aged 21; John 65 and Margaret 50 are together in ward 6 and it seems that Agnes was in the county jail.

That was the last I found of them.  A Margaret Orr, listed as 58, died in Zanesville in 1893 ... but I don't know if it is her. What happened to the rest of them?