She left Walter in 1964, divorcing him a year later, and then relocating from San Francisco to Hawaii. In Hawaii, Keane became a devout Jehovah's Witness, which she remained throughout her life. She credited her faith and reading the Bible for giving the courage to speak the truth about her artwork.

The enigmatic artist died on June 26th, 2022 at the age of 94. She left behind a significant legacy, notably her 1986 court battle with ex-husband Walter Keane, in which she proved that he was fraudulently claiming her work as his own. The trial and Margaret Keane's oeuvre inspired the 2014 Tim Burton film “Big Eyes”.

Walter Stanley Keane (October 7, 1915 – December 27, 2000) was an American plagiarist who became famous in the 1960s as the claimed painter of a series of widely reproduced paintings depicting vulnerable subjects with enormous eyes. The paintings are now accepted as having been painted by his wife, Margaret Keane.