[3] On June 6, 1966, Sunny married Claus von Bülow, a former aide to oilman J. P. Getty, at the Brick Presbyterian Church in New York City.

His maternal grandfather, whose surname he took, was Frits Toxwerdt von Bülow, Justice Minister of Denmark in the government of Klaus Berntsen (1910–1913) and also came from a noble background.

[10] On December 26, 1979, after the family had come together for Christmas at their Newport, Rhode Island mansion, she was found unresponsive and was rushed to the hospital where she slipped into a coma, but was revived.

After days of testing, doctors determined the coma was the result of low blood sugar and diagnosed her as hypoglycemic, warning her against overindulging on sweets or going too long without eating.

[13] On the evening of December 21, 1980, while celebrating Christmas with her family at their mansion, Clarendon Court, in Newport, Rhode Island, she again displayed confusion and lack of coordination.

Because of the increased marital tensions between Claus and Sunny von Bülow in the fall of 1980, her children were suspicious that her brain injury was the result of foul play by him.

Her two eldest children persuaded Richard H. Kuh, the former New York County District Attorney, to investigate the possibility Claus von Bülow had attempted the murder of their mother.

After the gathering of evidence, Rhode Island prosecutors presented the case to a grand jury who returned an indictment, and in July 1981, he was charged with two counts of attempted murder.

Evidence presented by the prosecution consisted of circumstantial evidence, imputation of financial motive, extensive testimony by various maids, including Maria Schrallhammer who was a prominent witness at both trials,[14] chauffeurs, doctors, and personal exercise trainers, a black bag with drugs, and a used syringe, reported to contain traces of insulin, found in Claus von Bülow's mansion.

At the second trial the defense called nine medical experts, all world-renowned university professors, who testified that the two comas were not caused by insulin, but by a combination of ingested (not injected) drugs, alcohol, and her chronic health conditions.

[20] In July 1985, ten days after Claus von Bülow was acquitted at his second trial, Ala and Alexander filed a $56 million civil lawsuit against him, on their mother's behalf.

[3] Sunny remained in a persistent vegetative state until her death from cardiopulmonary arrest on December 6, 2008, at Mary Manning Walsh Nursing Home in New York City.