I only recently learned that parrots can survive in temperatures close to and below freezing, as long as they are properly acclimatized, which is pretty amazing since their usual habitat is tropical and temperatures never fall below what I would consider to be "toasty".
Also, this may have been mentioned in other posts I did not read, but I haven't seen any reference to where she lives, and that may play a big part in how warm the shed is. Someone mentioned a heat lamp being used as an indication that it is indeed cold, but I just want to say when we kept Remy in the sunroom he had a radiant heater for him while the temperature was 17 C, so I think it best not to speculate on the unsuitability of conditions without at least asking the OP and listening to what he/she has to say.
If I were the OP, I'd definitely be put off by the tone of some of the comments here.
To the OP, sorry this happened. I would recommend keeping a close eye on them and making sure nothing is out of the ordinary with regards to their breathing, feeding, or behaviour for the next little while. You say you don't have access to transportation to get to the vet, but perhaps some sort of plan can be arranged for future emergencies. Doing things like finding the contact information and clinic address a knowledgeable vet, lining up an emergency form of transportation, be it a friend, family member, or taxi, planning the route to the clinic (if driving or bussing), and having a suitable transport container ready for the birds are all things that will save you time in case of critical emergencies and for which you can prepare now. Do what you can now, and next time you go for a checkup for them, mention this incident, even it's been a while, so the vet can check for any signs of respiratory distress.