Kerry Lawrence, an attorney, confirmed her death, but he does not know the cause.
The Bedford, N.Y. police department said that at approximately 1:36 p.m. they responded to a call of a deceased individual found at the Kennedys' home. They are investigating an "unattended death." They are not releasing the identification of the body until family members have been notified.
ABC News says a spokesperson for Mary Kennedy's family released a statement, saying, "We deeply regret the death of our beloved sister Mary, whose radiant and creative spirit will be sorely missed by those who loved her. Our heart goes out to her children who she loved without reservation. We have no further comment at this time."
After 16 years of marriage, Robert F. Kennedy Jr. filed for divorce from Mary Kennedy in May 2010. They have four children, and Mary Kennedy is Robert F. Kennedy Jr.'s second wife.
Mary Kennedy struggled with drug and alcohol problems, according to the AP. She was charged with driving under the influence of drugs, and her license was also suspended for driving under the influence of alcohol. Both incidents happened around the time of her divorce.
An unnamed source told Radaronline.com that Mary committed suicide. That information has not been confirmed.
Robert F. Kennedy Jr. is reportedly currently dating actress Cheryl Hines.
Robert F. Kennedy Jr. is the son of former Sen. Robert Kennedy and the nephew of former President John F. Kennedy.