On Sunday evening, Mary Max, the wife of the pop artist Peter Max, left a lengthy voice mail message for a friend in London with instructions for what to do after she passed away.

For the past several years, Ms. Max had been embroiled in a vitriolic legal dispute over her husband’s art, wealth and legacy, as he has struggled with increasing dementia. A stepson and household staff had made accusations that she had been abusive to her husband, and even attempted to kill him, while she countered with accusations that the stepson had “kidnapped” his father.

But in her final voice message to her friend, said her lawyer, John Markham, she did not rehash that dispute. Instead, he said, she left farewell messages for people she loved: her husband; her closest friends; her brother, Daniel; and her 94-year-old mother, Ruth.

The police said Ms. Max was found dead of an apparent suicide in her Upper West Side apartment at Riverside Drive and 84th Street at about 8:30 p.m. on Sunday. The exact cause of death is under investigation by the office of the chief medical examiner.