Big Eyes is the story of Margaret and Walter Keane. Margaret painted all of her life and her husband convinced her that the art of a woman would never sell in the 1960s and began to promote the art as his own. It took being separated from him for several years before she was able to announce that the paintings were hers and not his. When he publicly said she was a liar, she sued him in federal court, where the judge asked them both to paint. Margaret completed a painting in under an hour; Walter feigned a shoulder injury and painted nothing.
Here is an interview that aired this morning with Margaret Keene and Amy Adams (who plays her in the movie.)
I recognize her paintings, but had no idea of the story that went with them.
Fun fact: Wikipedia attributes the Power Puff Girls' big eyed style to inspiration from Margaret Keane's paintings and that their teacher, Mrs. Keane, was named after her.