REPORT: 1940 US Census: Household needs correction by FamilySearch
"United States Census, 1940," database with images, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:KWTX-PXX : 8 January 2021), Nettie Screen, Peoria, Peoria, Illinois, United States; citing enumeration district (ED) 104-64, sheet 64A, line 1, family 52, Sixteenth Census of the United States, 1940, NARA digital publication T627. Records of the Bureau of the Census, 1790 - 2007, RG 29. Washington, D.C.: National Archives and Records Administration, 2012, roll 919.
Nettie should be in a different household than William and Della O'Connor ; therefore both women cannot be William's wife ... Nettie does not appear to have any other household members in this Census - so other sources will need to be researched to locate her correct husband.
"Illinois Deaths and Stillbirths, 1916-1947," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:NQRT-N9S : 9 March 2018), Nettie Smith in entry for Lackey M. Screen, 28 Mar 1941; Public Board of Health, Archives, Springfield; FHL microfilm 1,832,580.
This citation appears to establish that Nettie's husband - Mr. Screen - is NOT William O'Connor. Current Census EDIT functions do not allow separation of incorrectly indexed households such as this - therefore ...
...someone with appropriate access will need to make this correction.