Gov. Andrew Cuomo's ex-wife, Kerry Kennedy, was arrested Friday for driving while impaired by drugs after she accidentally struck a tractor-trailer and fled, police said. Kennedy is the seventh of 11 children of the late Sen. Robert F. Kennedy. State police said she was found Friday morning behind the wheel of her disabled vehicle on the side of a road in Westchester, just north of New York City. Authorities say 911 callers reported the car was driving erratically on Interstate 684 and collided with a tractor-trailer in the town of North Castle. The car was damaged and had a flat tire, police said. A spokesman for Kennedy, who lives in nearby Bedford, denied that she was driving under the influence of drugs. "Kerry Kennedy voluntarily took breathalyzer, blood and urine tests - all of which showed no drugs or alcohol whatsoever in her system," spokesman Ken Sunshine said in an emailed statement. The charges were filed before the test results were available. Police said Kennedy was issued traffic tickets that must be returned to the town of North Castle Court on Tuesday. Members of the Kennedy clan who reside in the Westchester area have been beset with a string of public troubles in recent weeks. Mary Kennedy, the estranged wife of Robert F. Kennedy Jr., hanged herself in May at the family's estate in Bedford. A divorce was pending when she died. An autopsy report released last week showed she had antidepressants in her system. Kerry Kennedy, 52, described her sister-in-law as her "best friend" in a eulogy published in the Huffington Post after her death. "We were inseparable - we shared friendships, a closet, a cash card," Kennedy wrote. Her brother Douglas Kennedy, the 10th of the 11 siblings, is embroiled in a legal battle after two nurses claimed he injured them on Jan. 7 when he tried to take his newborn son from a hospital maternity ward. Kennedy, 44, said he was protecting his son "from a complete stranger who tried to grab him from my arms." A judge is expected to rule by Aug. 9 on charges of physical harassment and child endangerment. Kerry Kennedy and Andrew Cuomo wed in 1990 in Washington, joining two of America's first families of politics in a union dubbed Cuomolot. The couple split in 2003 in a messy public divorce that played out in the tabloids. They have three daughters.