Her RI did start with her previous owner if my observations were correct. The move half way across country might have made it worse but it never seemed too bad and she continued to eat which is why I didn't worry. I am beating myself up because I noticed the signs of a RI 4 months ago when I got her and if I had done something about it instead of hoping that a proper environment would make her better, it never would have gotten as bad as it was yesterday.
This morning she seemed that same as last night, which when compared to how she was at the vet is significantly better. I wish I had taken out my phone to video how she was when she was coughing so others could see. I jumped and cringed every time she did and I kept fearing that was the end for her.
I honestly think the biggest danger for her right now is if she decided to try to cough up more mucus. If she does it while I am home I should be able to either get her to the vet or clear what she coughs up away like the vet did.