Indeed, it was O'Connor herself who recently went public with the news that her husband John, 77, who suffers from Alzheimer's disease, had struck up a relationship with a woman patient at a care facility in Arizona.
"Mom was thrilled that dad was relaxed and happy and comfortable living here, and wasn't complaining," one of the O'Connors' three sons, Scott, said on television.
Before meeting his new romantic interest, who also suffers from Alzheimer's disease, John O'Connor was depressed and had talked of suicide, his son said.
Sandra Day O'Connor left her seat on the Supreme Court last year to look after her husband, who has suffered from Alzheimer's disease for 17 years.
The former judge chose to reveal her husband's "infidelity" to raise awareness of a lesser-known side of the degenerative brain disease, but did not comment publicly about the new woman in the life of her long-time partner.
Experts say it is not uncommon for Alzheimer's patients, who suffer memory loss and tend to live for the moment, to embark on new romantic relationships.
"I can't quantify how often this type of situation occurs, but it will continue to occur in greater number as the years go by, and particularly with baby boomers coming into long-term care settings," Rubin Dessel, head of memory care services at the Hebrew Home care facility in New York, told AFP.
Peter Reed, director of programs at the Alzheimer's Association, agreed that it was difficult to estimate how common the phenomenon was, but explained how it might come about.
"Alzheimer's is a progressive disease that affects the memory. Sufferers can forget familiar people, and live in the moment," he said.
"But people with dementia still need social connections, still need to interact and have meaningful relationships," he added.
Relationships between Alzheimer sufferers can take the form of an almost child-like romance where the couple simply holds hands.
But sexual relations are not unheard of.
"Sex? People certainly develop new relationships and they can take a variety of different forms," said Reed.
"They are not children despite having a memory problem," he said.
"While hand-holding is one demonstration of caring and camaraderie and intimacy, it may well extend to something more physical," said Dessel.
To families, watching a father or mother, husband or wife begin a new life with a new person, even as they have difficulty remembering their children and spouse, can be hurtful.
"If the marital relationship was a happy one, this can be extraordinarily hurtful and the family can react with sadness and pain," said Dessel.
But, she said, an Alzheimer patient who embarks on a new relationship is not truly cheating on their marriage.
"These relationships are not based on adultery or betrayal. Alzheimer's patients lose so much of their past and very often have no memory or recall of anything of their lives, apart from their day-to-day experience.
"They live in the moment without the luxury of their past lives," Dessel said.
She praised O'Connor's reaction to her husband's new object of affection.
"I applaud her. I believe that her support is noble and selfless. She is really looking to support the health of her husband and is concerned only at this point with his happiness and well-being," said Dessel.
"You have to be like Justice O'Connor. You have to be selfless."