1900 census for Decorah, Winneshiek Co, IA: ANDRUS, Joseph E. b. Feb 1859 in IA, married 13 yrs, both parents b. NY wife Mary A. b. Oct 1862 in WI, 3 children born, 3 children living, both parents b. Ireland dau Clara L. b. Dec 1887 in SD dau Alice M. b. July 1890 in IA dau Elsa A. b. Jan 1892 in IA
The 1910 census for Rock Grove, Floyd Co, IA: ANDRUS, Mary age 47 b. WI, widow, both parents b. Ireland dau Clara L. age 21 b. SD dau Alice M. age 20 b. IA dau Elsie A. age 18 b. IA dau Edna E. age 8 b. IA
The 1920 census for Mason, Cerro Gordo Co, IA: ANDRUS, Mary A. age 57 b. WI, widow, both parents b. Ireland dau Alice M. age 18 b. IA dau Edna age 18 b. IA
In the 1930 census it looks like Mary and her daughter Clara were living as boarders in a convent in Des Moines.
There's an IA birth record for Elsa Abigail ANDRUS b. 22-Jan-1892 in Sioux City, Woodbury Co, IA, daughter of Joseph Edwin ANDRUS and Mary Ann O'REILLY.
The 1860 census for Decorah, Winneshiek Co, IA: ANDRUS, Erastus V. age 40 b. NY Abigail M. age 31 b. OH Matilda H. age 14 b. IL Mary E. age 12 b. IL Esther M. age 10 b. IL Leah L. age 9 b. IA Daniel A. age 4 b. IA Asenath A. age 5 b. IA Joseph E. age 1 b. IA TRASK, Nathan A. age 19 b. OH BENTLEY, Marcus L. age 17 b. OH
The 1870 census for Center Township, Henry Co, IA has an Eratus P. ANDRUS, age 52 b. NY living in an insane asylum.
In 1870 Abigail and children:Mary, Elsa, Leah, Joseph, Josephine, Anne and Britimart are in Decorah, but their surname is spelled ANDREWS.
The household in the 1885 IA state census: ANDREWS, Erastus B. age 66 b. NY Abigal M. age 56 b. OH Joseph E. age 25 b. IA Harriet G. age 3 b. IA
The household in the 1895 IA state census: ANDREWS, Abagail M. age 67, widowed, b. OH Harriet G. age 13 b. IA JURGENS, John A. age 11 b. MN JURGENS, Lilly B. age 9 b. MN
The marriage record for Elsie ANDREWS to Stephen DECKER on 26-Mar-1890 in Decorah lists her parents as Erastus V. ANDREWS and Abigail M. FRANK.