Mary Kennedy, right, from whom Robert F. Kennedy Jr. filed for divorce in 2010, was found dead on Wednesday, May 16. A medical examiner said she died of asphyxiation due to hanging. She was 52. 
Members of the Kennedy family attend U.S. Sen. Ted Kennedy's funeral in August 2009. Two years later, his daughter, Kara Kennedy, died of a heart attack after her daily workout. She is shown being embraced by her daughter, Grace, at right. 
Michael Kennedy, one of RFK's 11 children, died in a skiing accident in Aspen, Colorado, in 1997. The father of three had suffered an onslaught of negative publicity over an alleged affair with a family babysitter. No charges were filed. 
Joe Kennedy, the eldest son of RFK, was involved in a 1973 car accident that left a female passenger paralyzed for life. He later served as a Massachusetts congressman and considered a bid for governor but decided against it, citing family troubles. 
Sen. Ted Kennedy drove a car off a bridge on Massachusetts' Chappaquiddick Island after a party in 1969. Aide Mary Jo Kopechne died in the accident. He is shown wearing a neck brace at her funeral. Controversy over the incident effectively ended his presidential aspirations. 
In 1964, Ted Kennedy suffered a broken back when his private plane crashed in Southampton, Massachusetts. Indiana Sen. Birch Bayh also survived the crash, but the pilot and one of Kennedy's aides were killed. 
Moments after this photo was taken, President John F. Kennedy was assassinated in Dallas on November 22, 1963. He was 46. 
- NEW: She was "a pioneer and relentless advocate of green design," RFK Jr.'s family says
- "It's very hard being ... a blood Kennedy or being married to one," biographer says
- Mary Kennedy wasn't divorced from Robert Kennedy Jr., family attorney says
- Robert F. Kennedy Jr. filed for divorce from her in 2010
(CNN) -- Mary Kennedy, from whom Robert F. Kennedy Jr. filed for divorce in 2010, is dead, an employee of the Westchester County, New York, medical examiner's office said Wednesday.
The employee, who declined to give his name, told CNN he would provide no further details about the manner and cause of death. Kennedy was 52.
The 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."
The Bedford Police Department earlier confirmed they were investigating a possible unattended death at an address owned by Robert F. Kennedy Jr.
Authorities found a deceased individual inside "an out building" on the property, police said in a statement.
Regarding her marital status at the time of her death, Mary Kennedy wasn't divorced from Robert F. Kennedy Jr., her family attorney, Kerry A. Lawrence, told CNN.
Mary Richardson Kennedy was "a tremendously gifted architect and a pioneer and relentless advocate of green design who enhanced her cutting edge, energy efficient creations with exquisite taste and style," Robert F. Kennedy's family said in a statement.
She advocated finding a cure for food allergies and asthma and was a co-founder of the Food Allergy Initiative, which is the world's largest private source of funding for food allergy research, Robert F. Kennedy Jr.'s family said.
"It is with deep sadness that the family of Robert F. Kennedy, Jr. mourns the loss of Mary Richardson Kennedy, wife and mother of their four beloved children. Mary inspired our family with her kindness, her love, her gentle soul and generous spirit," the husband's family's statement said.
The couple married in civil ceremony in 1994 when Mary Richardson, a designer, was six months pregnant, according to the Westchester County Journal News. One month prior to the wedding, Robert F. Kennedy Jr. divorced his first wife, Emily Black, the mother of his two oldest children, the newspaper reported.
Robert F. Kennedy Jr., a prominent environmental lawyer who's a professor at Pace Law School in White Plains, New York, is the third of 11 children born to Ethel and Sen. Robert F. Kennedy, who was assassinated when campaigning for the Democratic presidential nomination in 1968.
Details of the couple's private lives were exposed after Robert F. Kennedy Jr. filed for divorce in Westchester County on May 12, 2010.
The next evening, according to police records, Bedford police responded to a 911 call. When police arrived at the Kennedy residence they found the couple in an argument over taking their four children to a carnival at St. Patrick's School.
According to a "domestic incident" report filed by the officer on the scene, "Mr. Kennedy stated that his wife was intoxicated and was acting irrational so he took the children to the carnival to remove them from the situation."
No one was injured, the report said.
Two days later, Mary Kennedy was arrested for driving while intoxicated. At the time, Bedford Police Lt. Jeff Dickans told CNN that Mary Kennedy was arrested around 9:15 p.m. on May 15, 2010. Dickans said that a Bedford police officer saw Kennedy's 2004 Volvo swerving onto the curb of Greenwich Road in Bedford and asked her to pull over.
Kennedy had slurred speech, and a blood-alcohol content above 0.08 percent, the legal limit in New York. She was charged with driving while intoxicated.
Kerry Lawrence, Mary Kennedy's family attorney, said the case resulted in a reduction to a violation, the criminal charge was dismissed and her driver's license was suspended for 90 days.
A second arrest occured in August of the same year in the town of Pleasant Valley, in which she was charged with driving while impaired by prescription drugs, Lawrence said. Those charges were dismissed completely in July 2011 because all the drugs were prescribed and taken as her physician advised, the attorney said.
As a designer, Mary Kennedy specialized in green architecture, and in a book entitled "Kennedy Green House" and co-authored by Robert F. Kennedy Jr., he describes how he and his wife restored their flooded, black-mold-infested home into an eco-friendly residence.
In the book, her husband wrote that Mary Kennedy had worked for the design firm Parish-Hadley and worked on the renovation of the Naval Observatory in Washington, the official residence of the U.S. vice president.
"We know from a history of this family, it's very hard being a Kennedy, either being a blood Kennedy or being married to one," Laurence Leamer, a Kennedy biographer, told CNN.
