Possible. Humans have a far larger record of predatory behavior toward humans. Female and alone doesn't lower the odds either.

But there is also the chance she might have hurt herself. I don't know anything about the area or her familiarity with it but I have seen plenty of trails where you could carelessly run off an embankment, broken an ankle while running if you planted a foot in a hole, or stumble over debris and brained yourself.

I have read where a Florida man slipped crossing a stream, knocked his head on a rock, and would have drowned if his hiking partner hadn't pulled his face out of the water.

Lots of ways to get seriously hurt. Once hurt your an easy target for human and animal predators alike.