If you are unable to take her in permanently, please take her to a local rescue agency so she can get medical care. She definitely needs to be on antibiotics if she has an upper respiratory infection, and she will not get better if she isn't kept indoors and medicated properly. If you are unable to take her in yourself, call the agency and ask if they can come and get her. If her nose becomes too stuffy, she won't be able to eat. Cats must be able to smell their food in order to eat, so it's important that she get treated soon.
Please let me know if I can assist further.
Canine Health Care & Guidance
Qualified by many years of healthcare & experience in breeding dogs