A Terragrigia Survivor is an article in Resident Evil Recollections. It was uploaded on 1 April 2015.
As the story starts to shift gears in Episode 2, we find out that Natalia is one of the survivors of the Terragrigia Panic.
In case you haven't played Revelations 1, the Terragrigia Panic was a bioterror attack that resulted in the destruction of an entire city, much like the Raccoon incident. Now why would someone like Natalia be taken to this island?
If you want to get to the bottom of this you'll just have to keep playing!