Wow, what an amazing street portrait of a very gorgeous young woman. Love the shy smile yet the confidence in her beauty in the eyes. Good use of thirds and of the ambient light, though if you had had the time during the shoot to either shoot at a higher ISO, and faster or with a smaller aperture, to help damp down those few glarey areas on her. Or try bracketing, see if that helps as in such a situation neither of you may have that much time to spare while you play with settings. It was an Advanced challenge too so some dodge and burn on the face and glarey areas would have been fine. It also looks like it would translate well to b/w.
It's a lovely street portrait, but I particularly like it with the title. Somehow it sent my mind racing. Who is she? What provides her identity. Her shoulders became eyes.
Took me a while to make this connection. I wonder how many people will be looking for a movie reference instead of understanding that you took the title as inspiration.
Not sure which movie you are going after, there are two I know of titled "Unknown" but I never really watched them. I think it's a nice picture, there could have been some skin smoothing, or a warmer tone. Maybe even a black and white conversion. I think the natural light makes for harsh tones on the model's face. Just my personal opinion, however.