Isabel Moenke was born 31 July 1899, just in time to be recorded in the 1900 census. It was the only one in which she would appear.
Her parents, Leo and Emma (nee Kaeding) were married in Chicago 01 Oct 1898  and Isabelle was their first child.
The couple went on to have more children.
I’m certain darling Isabel remained always in their hearts.
 “Illinois, Cook County Marriages, 1871-1920,” database, FamilySearch (https://familysearch.org/ark:/61903/1:1:N7WK-YJG : accessed 23 May 2016), Leo J. Moenke and Emma Kaeding, 01 Oct 1898; citing Chicago, Cook, Illinois, 281350, Cook County Courthouse, Chicago; FHL microfilm 1,030,288.