Hi again, Dom and you're most welcome!
It's my pleasure to be of help to you and Callie!
She does sound like quite the butterball! : ) I'm glad her thyroid was normal, when she was tested, and also be on the lookout for diabetes, which older, overweight cats are more prone to develop. I'm glad you're watching her diet and a canned or dry food grain free diet would be best for her. Some good ones are Wellness, Wellness CORE, Felidae, Blue Buffalo, and many more available at your pet supply store. This article written by a veterinarian should be of interest to you; it deals with how best to feed our cats and also includes certain medical conditions:http://www.catinfo.org/
If Callie likes to play with/eat elastic bands, that is very dangerous. My part-calico used to love to do that, too! You need to make sure you keep all items of that type inaccessible to her. It may possibly be causing her present symptom.
Also, her voice is hoarse because she's coughing and irritating her throat.
Monitor her tonight and hopefully all will be well, but if you notice any of the symptoms I mentioned earlier or any other unusual ones, definitely bring her to the ER vet center.