1910 in Bennington Township - and Henry's sister?

By the time of the 1910 Federal Census, the Landau family had moved to the other side of Waterloo to Bennington Twp.

Henry W.  - 40 - a farmer - can read & write
Katherine - 33 - year of immigration: 1890; can read and write
Vera E. -  14 - attending school
Jerome V. - 12 - attending school
Everett F. - 10 - attending school
Clarence A. - 8 - attending school
Wilbert A. - 5
John W. - 4
Carl O. -  1

While searching the 1910 census, I found what  appears to be Henry's sister:

Landau, Katie - 43, a private nurse - b. in Illinois, parents b. in Germany, in the household of 89 year old Hiram Champlin.

Henry had a sister Katie, same age, who never married, also born in Illinois, and then there's the Champlin connection.  Although I don't have proof, I think it is strong circumstantial evidence that nurse Katie was indeed Henry's sister.

DOCUMENTS:

• 1910 Federal Census - Bennington Twp., Black Hawk County, IA
• 1910 Federal Census - East Waterloo, Black Hawk County, IA