I checked on street view on Google Maps, and as I suspected it isn't the best of areas. While NYC is generally safe, she wouldn't have any fun living there and would always be nervous. The biggest problem is that living in any nice part of NYC is expensive. Have her look in Brooklyn and get back to me on what she finds. I'll give you a good assessment.
I would ask my wife if we could take her in, my teenage daughter spent a summer in France, but we just had a big argument about having someone else come live with us. We live in Brooklyn in an area where the younger post-college crowd has started moving in.