BOSTON (AP) — Joan B. Kennedy, the former wife of Sen. Edward M. Kennedy who endured a troubled marriage marked by family tragedies, her husband’s infidelities and her own decades-long struggles with alcoholism and mental health, died on Wednesday. She was 89. The former Joan Bennett, one of the last remaining members of a family generation that included President John F. Kennedy, was a model and classically-trained pianist when she married Ted Kennedy in 1958. Their lives would change