May have a few answers here:
1930 Omaha, Douglas, NE dist 26 pg. 7A shows Ben Collatz, wife Esther, son Donald and mother-in-law Sara Cowles (mother of Esther). Sara is listed as divorced. On the search, Esther is listed as EATHER. The census shows her age in 1930 as 19, so her birth yr would be 1910 or 1911.
Ben was born 5 Mar 1906 in Iowa, died Dec 1982 in Davenport, Scott, Iowa. Esther was born in Iowa. Donald was born 26 Nov 1929 in NE, died Apr 1977. Sara was born in Iowa.
1920 Atlantic, Cass, IA ed# 34 pg. 6A shows a Carolina Grittmatter, daughter Sarah Collatz, grandaughter Sophia J., grandson George L., and grandson Benjamin L. (Sarah Collatz is Ben's Mother / Sophia is Ben's sister).
Carolina was born in Prussia, naturalized in 1866. She was listed as widowed. The husband was born in Baden Germany. Sarah was born in Iowa. She was also a widow. Sophia, George, and Ben were born in Iowa.
1930 Atlantic, Cass, IA dist 3 pg. 5B shows Carolina Grittmatter, daughter Sadie Collatz, grandaughter Sophia, and greatgrandaughter Alice. (Sophia is the Sophia Schwenneker).
Sadie is listed as widowed. Sadie, Sophia, and Alice were born in Iowa.
Sophia Schwenneker is shown in the SSDI:
born 24 Sep 1902, died 17 Oct 1988 Aledo, Mercer, Illinois.