How long will she stink?

I assume you bathed her?  How old?  Any flakey spots near the face?  In other words, I'm saying be careful because it could be more than just food, but a general health problem.
 
A lot depends on how long she was with them, what she ate before, the general state of her health, etc. -- the answer will vary from a few days to a few weeks/months.
 
Have you had a fecal done?  I never bring anybuddy home til they have fecal so my dogs aren't getting parasites.  Been there, done that and lost one once because he was old and got hooks from a dog we took in during a hurricane.  *sigh*  I lost him in just a couple of weeks -- he was old, it was a hot summer and I mistook his lethargy for just an "old dog having a tough time with the heat".  So now I"m over-cautious.

Yup, I bathed her but she still smells awful "doggie", but maybe she is not completely dry yet (I'm hoping).  She looks like she has dandruff on her body, where it really shows up because she is black.  I supplement with fish body oil so maybe that will do the trick.
 
 Zoey was brought to a vets office by a dog catcher to be euthanized, but the vet tech decided she was too sweet to be put down so she got her into rescue.  Nothing is known of her history before that.  She was vetted on February 28th (clean bill of health) and spayed March 2nd.  They are guessing she is about a year old. I am taking her to my vet as soon as I can get an appointment for a good once over and I think I'll get another fecal done just in case (the foster home had lots of animals).  I remember you warning about hook worm on another thread and I have an old guy here, too, so I'll be sure to double check that. 
 
I am also concerned because she seems to breathe rapidly.  She was sleeping right next to Roxy today and Roxy is smaller yet Zoey was breathing twice as fast.  I'm thinking that that is not right.  Any ideas?  She doesn't have a runny nose or any signs of illness and she did just go to the vet... but I'm a worry wart!

What a fantastic story, and she is now in such a good place. I am so happy for the both of you. I would love to see a photo.

I think that it can take a little while for them stink to go away. [&:]

This is justa theory, but there are two reasons:

1) When doing an elimination diet for alleriges it can take up to 8 weeks for results to show, so I would assume that this is the same for your dog. It may take a while to get the bad (excuse me) crap food out of her system

2) We adopted a hound who I thought smelled awful! I don't know what he was eating. It took a while (like 3 months or so) but with good food and enzymes (and I snuck in a little chlorophyll too) he smells pretty now, just naturally.

Congrads!

I am also concerned because she seems to breathe rapidly. She was sleeping right next to Roxy today and Roxy is smaller yet Zoey was breathing twice as fast. I'm thinking that that is not right. Any ideas? She doesn't have a runny nose or any signs of illness and she did just go to the vet... but I'm a worry wart!

Is she an older dog? Some old dogs breath like that. Has she been in for a wellness exam yet? If not I would do so, so they can listen to her heart and lungs.

Other theory is that she might be stressed, either way i would get her in asap.

lazlowe1, you are right on the money.  The rapid breathing has gone away now that Zoey has been here for a few days and has settled in.  It must have been stress- poor baby must have been scared to death that first day! 
 
I have also noticed that she smells better.  It snowed heavily on Sunday and she was in and out all day so she got toweled off repeatedly.  I've also been using those pet wipes on her.  I'm thinking she was just very, very dirty and stinky.
 
I have an appointment for her with my vet tomorrow, even though she was just vetted and spayed at the rescue. 
 
Heres a picture:
 
 

She is precious! I am so happy for you!