She said that she got it at Bikes not Bombs. I'm not a mixtie expert, but this one looks like a step above your average Peugeot. The tube says Cyril Guimard (in pristine letters).
Look at that fantastic front light! And the fork crown lugs!
I could have taken a lot of pictures, but as they were stopped in the street, I didn't want to test her patience. What a lovely find!