My father was going to die anyway, due to cancer, but he was expected to live one more half of year. Nevertheless, he was stable and without any visible difficulties, so much that his spouse was completely unaware that he had cancer (he preferred to delay telling her, to keep her happy, without worries, as there was nothing to be done anyway).
Unfortunately, she died suddenly due to a hemorrhagic stroke, shortly before completing 65 years of marriage. Precisely after one week, he also died (due to some kind of kidney failure), after saying at her death that his wish had always been for them to die together, so his wish was fulfilled very soon.
I suppose that doesn't make it any less of a "mind-body connection," really.
Sorry for your loss.
I saw a western study looking at death rates and if I recall correctly: there was a dip in death rates just before 25th December, and then a bulge the same size as the dip after Xmas.