There are rumors floating around regarding the contents of the notes, but no confirmation. One tantalizing rumor I ran across recently claimed the note said something to the effect “They know everything. I’m sorry” signed George H.W. Bush. Who knows if it’s true? but it doesn’t sound that far fetched to me. Whatever it was, was short and succinct - and enough to spook the hell out of Jeb after just a quick glance.
It struck me that Jeb’s reaction to what Laura showed him was instantaneous. It took a millisecond for him to comprehend what he saw. His first reaction was to look back at the coffin, and then in the direction where Trump would have been standing.
Unless it was a single word, I don’t think it was something written. I think it was an image.
Notice Laura took a while to absorb what she was seeing. For Jeb, it was immediate.