Willoughby was born and raised in West Branch, Iowa, the daughter of farmer Verlin Luther Pemberton and Sara Margaret Hinshaw.
From 1971 to 1987, Willoughby and her husband were central to a group of 20 houses practicing communal living in West Philadelphia, called "The Life Center," devoted to helping the community.
During the auction at the IRS headquarters in Chester in 1970, the Willoughbys and supporters served lemonade in the hallway before submitting the winning bid of $900 to buy the car back.
In a statement read in court, she summed up her philosophy: "I am approaching my 90th year… I had high hopes of leaving this earth confident that the people on it knew more about nonviolence and conflict resolution.… Even after 9/11 we had a window of opportunity to do just that.
In 2006, she and other older activists, including the poet Sonia Sanchez were charged with defiant trespass for refusing to leave a Center City military recruiting station after trying to enlist to serve in Iraq.