A Rescued Stranger

Eren sees a girl all alone outside of the walls. She's malnourished, weak, and faintly ill. She also can't remember anything: why she's there, who she is, or how she got there. Eren is determined to help her get her memory back; but Mikasa and the others are worried she's more than what she says she is. But her memory is the key. Could it be a answer to their questions? OC!