When immortality is given, it violates the natural law. All living things must die, so Nature finds a way to keep balance by creating mortal shadow selves. Dopplegangers. They’re powerful, mystical, naturally recurring.
Hospital (you choose the planet)
The heart monitor pattered away in rhythmic sounds. The woman lying on the bed could look as if she were sleeping, had she not been in a coma. Medical staff came and went, making notes on her chart as they measured vital signs. On the chart she was listed as “Jane Doe” since nobody knew who she was. All they knew about her was that she must be a Force user because a lightsaber had come in with her. It was lying on the table next to her bed but it looked extremely odd. The technology didn’t seem of this galaxy, and perhaps seemed ancient compared to what was used now by the Force users of the galaxy. Her clothes were also weird. The hospital saved what they could, though most had been covered in blood from the accident. They normally wouldn’t bother but the fabric was just so odd they didn’t want to throw it out. Wherever this girl was from it certainly wasn’t local.
The local investigators had searched around, looking for some family or friend to come claim the woman. Her coma was medically induced and soon the doctors would be waking her but after that they had no idea what to do with the girl.