Iowa State Census Collection, 1836-1925, on Ancestry.com for 1855 lists Randina Dahl b. abt 1855 m. Henry b. 1854, with the following all born in Norway:
Agnes b. abt. 1876
Henry C. b. abt. 1879
Oscar D. b. abt. 1881
Andrew b. abt. 1881
Ingeborg G. b. abt. 1883
Carl B. b. abt. 1885
Agnes Matilda Dahl, m. Warren O. Lewis in Estherville, Emmet, Iowa. 15 June 1893
Check CD Lewis Public Family Tree on Ancestry or Roots web but confirm the information for your self.