In genealogy research, you CAN NOT ASSUME.You must PROVE what happened. I've posted this to you on MANY times.
She could have married.She could have died.She could have returned to Wisconsin.She could have changed her name.Her name may have been so badly spelled or transcribed in the 1920/1930 Census, she was found (If you would notice, her name was written what could be viewed as Povlitske in the 1910. She could have gone to Canada.
There were many influenza outbreaks in the late teens in the USA.
"IF" this is "Positively" her, or just someone with the same name, why is she by herself and out in Washington State.
Someone could check the city directories to see when she arrived, when she disappeared.
Research is always more reliable than when someone "assumes".That word identifies someone that does not take genealogy research seriously.