I believe she and her husband are in the 1880 Census of Columbia Co., PA. However, they may be in the home of Hannah's mother, Anna Bodine. Anna is listed as age 70 and born in New Jersey. The three Ervin children are listed as grandchildren which makes it seem like this could be Anna's household rather than John Ervin's. The three children are Rose (b. 1858, PA); Peter B. (b. 1865, PA), and Isaac G. (b. 1870, PA).
I think the following applies to this family:
PETER B. ERVIN, harness-maker, Catawissa, was born August 21, 1864, in Catawissa, a son of John and Henrietta (BODINE) ERVIN, natives of this county, and of German and English descent. His great-grandfathers came from the old country and settled in this county, near Catawissa, and Jonas METZ, a brother to his great-grandmother, was the first farmer in the vicinity of Catawissa, and lived and died here. The great-grandfather lived to be ninety-four years of age, and was a soldier in the Revolution. Our subject's maternal grandfather was a cabinet-maker but during the latter part of his life followed farming. His paternal grandfather, Isaac ERVIN, is yet living at the age of eighty years; is stout and strong, and does a good deal of his farming. He owns a farm, a part of which lies in Locust Township and a part in Catawissa. He learned the mason's trade and worked at it in his younger days. He helped to build the furnace at Danville, and, while so engaged, he had three ribs broken and was otherwise injured. Our subject's father was born on the homestead in Locust Township, and learned the carpenter's trade. He served in the war of the Rebellion, and after marriage moved to Catawissa, where he since worked at his trade. He is now employed by the Philadelphia & Reading Railroad, as car builder. Our subject was reared in Catawissa, attended school until seventeen years in the confectionery business. In October, 1885, he commenced to learn the harness-making trade, and has since been engaged in making and selling harness. He is a member of the Evangelical Lutheran Church; is also a member of the P. O. S. of A. In politics he is a Republican.(History of Columbia and Montour Counties Pennsylvania, Battle, 1887 Catawissa Township pg. 399)