A Question About Garnet's Future Vision

It has been a while since I've seen the episodes that go into detail about Garnet's future vision, so forgive me if I don't take certain things into account. We know that when Garnet sees the future, she sees many possibilities. However, do her predictions only take into account her current knowledge?

Let's say that she is left alone with an object and decides to leave the room. Someone comes by and steals the object without her sensing it in any other way. In the time before she re-enters the room, do all her predictions about that object involve the object having been stolen and thus she knows that the object was stolen without using her other senses? Or do some of her possible futures involve the object still being there since she hasn't found out about it being stolen yet? If it is the former, does this mean that it is impossible to trick her? If it is the later, does this mean that her future vision no different than regular, non-magical prediction-making?

I've been thinking about this since I heard that Garnet doesn't ask questions (something I didn't even notice until it was pointed out in one episode). Also, future vision, no matter what type, is one of those powers where it is fairly easy for a book/TV writer to write themselves into a corner, especially if there are reveals to be made later on.