1880 Census, Muscatine, Muscatine Co., IA [clearly spelled Held]: Conrad b. Germany, 1816/17 Catherine b. Germany, 1829/30 Children b. IA: Kate b. 1866/67 [24 Aug 1865?], Emma b. 1875/76 [24 Nov 1875?], August b. 1867/68, William b. 1872/73 and son Adam b. Germany 1859/60
1870 Census, Muscatine also as Held: Conrad, Kate, and children Sebastian b. 1853/54, George b. 1855/56, Rhinehat [indexed Rhinchat and probably Rhinehart?] b. 1857/58, Artimer [probably Artemus?] b. 1859/60, all born Hesse/Hessen; and Kate, b. 1865/66 [although indexed as 9 not 4], Agust b. 1867/68 and Ernst b. Mar 1870, all in IA.
In 1900, Emma Hild b. 1875/76 is with sister Katharine Miller and her family at Bradford, McKean Co., PA, then on 21 Aug 1906, Emma Hild marries Herman D. Rueckert at the home of her sister, Mrs. Carl Miller, at 707 Lion St., Dunkirk, Chautauqua Co., NY.
Emma’s 1961 obituary gives Hild, at which time she is survived by her daughter, Helen Katherine Kaltenbach, 2 brothers and 1 sister.
The Millers and Rueckerts are all buried in Forest Hill Cemetery, Fredonia, NY and the online cemetery records say that both Emma and Katherine were born at Muscatine, IA; then to further complicate things, Katherine Miller’s parents are given as Conrad Miller and Katerine Sibman while no parents nor maiden name are given for Emma. I suspect that Emma provided Katherine's information so that may be their mother's maiden name but the Miller is a clerical or transcription error.
If someone can confirm the correct spelling, I’ll finish linking the family members at Find A Grave and happily share the details that I have found about this family.