Days, monthes, come on, doctors do tend to give estimates when they can and that's just nitpicking.

As for doubts about them not finding them before, well I doubt she would have known her own time was coming so well as to do it in one big go just before. They never said they only found such notes after she died or that it came as a surprise to them. I have to imagine she had started hiding the notes awhile back and they started finding them before she died. That doesn't make the statement that they found hundreds of notes after she died false nor does the fact they it wasn't a total surprise reduce the comfort it must have been to her parents.

So, of course, it's been exaggarated, nothing in the media isn't spun in some way, but it's not like this is a fabrication.