The couple met after Mr Graham started writing to her after being told her husband was his heart donor. Twelve years after the successful transplant operation, Mr Graham shot himself dead, leaving his wife a widow for the second time in strikingly similar circumstances.
Friends said Mrs Graham, a nurse, is stunned by the bizarre turn of events. Officials in Vidalia, Georgia, said Mr Graham, 69, died after shooting himself in the throat with a shotgun.
He was found in a garage at the home the couple shared.
In 1995, Mr Graham had been on the verge of death due to congestive heart failure.
He had less than six months to live when the call came through from the Medical University of South Carolina, telling him that a heart had just become available.
It belonged to Mr Cottle, 33, who had committed suicide by shooting himself in the head.
Mr Graham went to the hospital from his home nearby and the heart was transplanted that day.
He did not know the identity of the donor, only that the heart belonged to a 33-year-old man.
A year later, Mr Graham contacted the organ donation agency wanting to thank the man's family for the gift of life.
He began writing to Mr Cottle's young widow Cheryl, a mother of four. The couple later met, fell in love, married and moved to Georgia.
Speaking shortly after their wedding, Mrs Graham said: "It helped me so much.
"Meeting Sonny made it easier for me, knowing something so good came from something so bad."
Friends of Mr Graham said he had not shown any signs of being depressed.
Scientists say there are more than 70 documented cases of transplant patients having personality changes as they take on some of the characteristics of the donor.