I'd get her in and see if you can do a payment plan..or maybe sell plasma is you have that as an option (lol I have done it for money ha)
They hide illness and so the fact that you are seeing a change +sneezing and inflammation means something is not right. They don't just get "colds" like people..
It's possible that she has something in there, but the fact that it has gone on for more than a day concerns me.
Birds don't normally sneeze daily...maybe once or so...(barring a few sneezes in a row on a single day where they get something stuck in there).
When my bird has sneezed more than 3x a day for more than one day, she has always ended up needing medicine...so that is just my take.
Do make sure your house is warm enough and not drafty, but if she is sick, it won't cure her...Chills etc can drop their defenses/stress their bodies, but an infection still would need to be treated. Laurasea is right about vitamin A too, but it could be time-sensitive, which is why I don't know if waiting and changing diet without a vet is a good idea (I mean, yeah, get her the best diet possible) but if it isn't vitamin A then waiting could be problematic.