She loses 1 point on her vault, but since the scores are summed up and then averaged, she actually loses 0.5 out of the final score. She would be in a comfortable place for silver.
Alternatively, the judges may see this as a touch rather than a fall. Either way, with a touch she loses 0.5 off of her score for one vault, 0.250 from the final score. She would still earn silver comfortably.
I am really happy for her reaching 4th place at the Olympics, though. She knew it was going to be really hard to get a medal. I hope she gets a medal at the Worlds next year. Hong will probably retire, Biles will get some time off, Steingruber might retire as well, Paseka most certainly will retire too, so Dipa would be a shoe in for a medal.