[QUOTE
Your mother herself is the source of the mistake. If she made big dramatic statements about how the transplant was the universe’s birthday gift to her or some such, most people would think it happened on her birthday.[/QUOTE]

That is such a good and smart point.

Family stuff is so difficult and sad when it undermines even your sense of what's real. Like others said, just bc the timing isn't exactly right in your memory, doesn't negate how real the feelings and larger experiences were, and those are what count.