The recent troubles of the Kennedy clan played out in two courts in New York on Wednesday in cases involving sisters-in-law who were close friends.

A test of blood taken from Kerry Kennedy after a drugged-driving arrest showed traces of a sleeping drug, contradicting her own doctors' findings. And the oldest son of Robert Kennedy Jr. and estranged wife Mary Kennedy stepped forward to take over the estate Mary Kennedy left behind when she hanged herself.

The blood test, filed in North Castle Town Court and first reported by Newsday Westchester, showed that a toxicologist detected 14 nanograms per milliliter of zolpidem, the sleep aid found in Ambien, in a sample taken the day Kerry Kennedy's Lexus swerved across Interstate 684 and swiped a tractor-trailer.

That amount is low, typical of someone who would have just taken a pill or taken one several hours before, said Dr. Michael Thorpy, director of the sleep disorder center at Montefiore Medical Center in New York.

A urine sample was negative for alcohol, the toxicologist wrote.

Kerry Kennedy, ex-wife of Gov. Andrew Cuomo and a daughter of Sen. Robert F. Kennedy, asserted a week ago that her doctors thought the July 11 accident was caused by a seizure. She said their tests found no alcohol, recreational drugs or prescription medication in her system.

She acknowledged, however, that she told a police officer she might have taken an Ambien pill by accident instead of her daily thyroid medication.

"It now appears that my first instinct was correct," Kennedy said in a statement issued late Wednesday. She said she had sought other explanations for the accident when the first drug tests came back negative.

Police said Kennedy failed several sobriety tests and was swaying and slurring her speech.

Kennedy, 52, pleaded not guilty July 17 to a charge of driving while drug-impaired. She was released but was ordered to undergo evaluation by a substance abuse agency. She is due back in court Aug. 14.

Earlier Wednesday, in Surrogate's Court in White Plains, a dispute over who would handle Mary Kennedy's estate was settled at least temporarily when Conor Kennedy, her son with Robert F. Kennedy Jr., applied for the job.

Conor Kennedy's lawyer, Brandon Sall, said his client turned 18 on Tuesday, qualifying him to administer the estate of Mary Kennedy, who hanged herself in May in the midst of a divorce.

A lawyer for Robert Kennedy _ who would normally be the court's first choice to handle the estate _ raised no objection, and Judge Anthony Scarpino said he expects to grant Conor Kennedy's application.

Sall said attorney Faith Miller would assist Kennedy.

Meanwhile, Mary Kennedy's divorce lawyers dropped their application that a public administrator be appointed. They had objected to the possibility of Robert Kennedy being named administrator because they claim he owes them $278,000 and would have a conflict of interest.

Mary Kennedy's sister, Martha Richardson, also was in court but did not go before the judge. She said afterward she hadn't decided whether she objects to Conor Kennedy's application.

"I think there are a lot of questions to be answered about the circumstances of my sister's death," she said. She would not elaborate.

Mary Kennedy, 52, who had four children, hanged herself May 16 in a barn behind the couple's home in Bedford amid bitter divorce proceedings and a battle with depression and addiction.

Although her family revealed some hard feelings toward the Kennedys, and lost a court fight to bury her at a site of their choosing, Kerry Kennedy publicly praised her as a mother and friend.

Mary Kennedy was buried May 19 in Massachusetts near her husband's aunt and uncle, Eunice Kennedy Shriver and Sargent Shriver. Seven weeks later, reportedly at her husband's direction, she was reburied 700 feet away near empty plots he is negotiating to buy.

Douglas Kennedy, brother to Kerry and Robert Jr., is also involved in a court case in Westchester County. He is fighting charges stemming from his attempt to take his newborn son from a maternity ward.