Don Rickles’ Widow Barbara Dies on What Would Have Been the Couple’s 56th Wedding Anniversary

Ron Galella/getty images

Don Rickles' widow, Barbara, died at the age of 84 on Sunday, March 14 – a significant day in their relationship, PEOPLE confirms.

Her death on Sunday marked what would have been the couple's 56th wedding anniversary.

The couple wed on March 14, 1965 and remained inseparable until Don's death in 2017 at age 90.

Before her death, which was first reported by TMZ, Barbara had been battling non-Hodgkin's lymphoma on-and-off over the years, had failing kidneys and other health conditions that resulted in her being hospitalized last week.

Ron Galella/getty images

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Don's rep Tony Oppedisano tells PEOPLE that Barbara's physician was amazed by how long she was fighting through her hospitalization.

"She's gonna hang around, I said, because of Sunday, the 14th," Oppedisano recalls of the conversation he had with Barbara's doctor. "I said that would have been her wedding anniversary."

He adds, "And lo and behold, I got a call at five o'clock yesterday morning saying that she passed away."

Oppedisano also shares that Barbara wrote in her Advance Medical Directive that she "didn't want any more treatment" due to her declining health.

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Barbara's funeral was held on Monday, Don's rep confirms.

After Don's death, Barbara took over his social media accounts and would often share touching moments about their relationship with fans.

Last year, she posted photos of their wedding on Twitter.

"Tomorrow March 14th would have been our 55th wedding anniversary. My Don and I were able to celebrate 52 wonderful years together," Barbara wrote. "He is always in my heart as I loved him so and still do."

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Throughout their marriage, Barbara and the beloved comedian welcomed two children – daughter Mindy and son Larry – the latter of whom died in 2011.