Hello, I am not related. I think I found Ethel and her youngest daughter Katherine in the 1940 census. It looks like Ethel was now married to a Charley Lavenson, and it also looks like they had a daughter together, Adeline, born about 1933. But I think his last name was Swanson, even though it is indexed as Lavenson.
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1940 United States Federal Census, Grantsburg, Burnett, Wisconsin
Street: State Highway 70
Inferred Residence in 1935: Rural, Burnett, Wisconsin
Residence in 1935: Rural, Burnett, Wisconsin
Sheet Number: 11A

Household Members: Name Age
Charley A Lavenson, head, age 45, born Wisconsin (White)
Ethel V Lavenson, wife, age 48, born Minnesota (Negro)
Adeline L Lavenson, daughter, age 7, born Wisconsin (Negro)
Kathern J Campbell, stepdaughter, age 12, born Wisconsin (Negro)