Did the death of her daughter possibly play a role in Reynolds' own death? In other words, can a person die of a broken heart? I think, indeed, broken heart syndrome is real and it exists. Broken heart syndrome can happen in response to any acute major stressors in someone's life.
While officially Debby sadly passed away due to a stroke, it is not too far fetched to assume that the shock of tragic loss of her daughter was what caused it. Times of emotional stress can push the strongest of us to our limits, so I do believe that it could be fatal for someone more frail.
After her death, I read that in the past she had a troubled relationship with her daughter Carrie. This leads me to believe that she died of heartbreak, she just couldn't accept that she had wasted all those years away from someone she loved. It can't just be a coincidence that mother and daughter would die within a day of each other.
Debbie Reynold's death was so soon after Carrie Fisher's death. It was obvious that she loved her daughter very much. She was making plans for her death but she was very upset and heartbroken that her daughter died. Anyone would be so upset to have to bury their own child. She gave up on living.