"There are multiple reports of a “hispanic woman” going around before the concert started saying that people were going to die. Could this be her?"
Not if she was in Asia at the time.
This woman could have fled to Harry Reid's basement immediately following the massacre. DO YOU BELIEVE ANYTHING THE FBI TELLS YOU?
All I know is, a woman screaming "you're all going to DIE" at a concert is a SERIOUS instance of NOT MERELY A COINCIDENCE.