Could they be prophecies about events that are still farther in the future?
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I would define a true prophet as someone who makes predictions about the future that are fulfilled, and a false prophet as someone who makes predictions that are not fulfilled. By that definition, she is a false prophet. And, since most people cannot see the future, the presumption is that someone who makes predictions about the future is a false prophet until proven otherwise. Thus, Ms. Jahenny is still a false prophet by that criterion.
As far as your theory that her predictions might come true later, if we accepted the idea that we can call someone a true prophet while their predictions are unfulfilled, then everyone who predicts the future must be considered a true prophet, which is absurd.
Moreover, if you look at true prophecies, they are always fulfilled within a reasonable amount of time. This is obvious, since there is no point warning people of chastisements that will not take place for another millennium. Prophecies are given to warn people to repent, and chastisements are given to people who ignore those warnings.
This is why true prophecies are usually fulfilled within the lifetime of the people who received and ignored the warnings. Our Lady at Fatima warned people of a terrible war that would punish the world if people didn't repent. That was fulfilled about 20 years later. At La Salette, she likewise warned of a terrible famine if people wouldn't stop working on Sundays. That was fulfilled about ten or twenty years later, I forget exactly. Our Lord warned the Jews that Jerusalem would be destroyed. It was destroyed 40 years after He predicted that. Jonas the prophet told the Ninevites under inspiration that Nineveh would be destroyed within 40 days if they didn't repent, but fortunately their repentance averted that chastisement.
That's how real prophecy works. But this woman has been dead since 1941; nearly everyone who heard her warnings is long dead. At a certain point it doesn't make sense to think her predictions were true. Otherwise, what, should we look through medieval manuscripts for some monk who prophesied the Indonesian tsunami in 2004, or the plandemic/jab, or the 9/11 attacks, or any other major disaster of recent years? Of course not. If anyone had predicted those things a thousand years ago, their prediction would long since have been lost to time and would have been idle at the time it was made, and even more idle now. So that's why it doesn't make sense to think that someone a century ago would be making true prophecies about things that would take place so long after their lifetimes that they and their prophecies would be long forgotten by the time the prophecies were fulfilled.
You kind of have to look at these sorts of things with a bit of common sense.