I don't really see any blackened or dead looking tissue that is usually associated with frostbite on the foot ( it would look something like this:http://www.backyardchickens.com/t/844688/frostbite-on-foot
Looks more like bumblefoot to me. Here are photos and instructions on treatment.
As for the wing try to wash/clean it in a saline or diluted betadine solution. You need to see what's under there, whether it is dead tissue or an infected cut, etc. Since she was stuck in the nest box, she may have been flapping around in there and cut it or tore the skin. Since it smells it would be infected.
Once you clean it up good, use an ointment like neopsorin (no "caine") or something like vetericyn spray.
Keep her isolated in a warm, quiet place and provide her with food and water. You could add vitamins or electrolytes to her water (Can find them at TSC).
Does she have a problem eating/drinking? Or any other symptoms, let us know.
Here are a couple of links for more info on treatment and medications.
Please keep us updated, if you can post better pics of the wound on the wing that would be great.