Hello and thank you for using this site to help you. One of the biggest signs of a disc issue to the owner is when their dog stops jumping on and off of furniture. You will also see a hesitance or refusal to do things that the dog loves to do such as your high five.
Smaller breeds are more prone to intervertabral disc disease which is when the soft tissue that cushions the disc suddenly or over time hardens and it presses on the spine causing pain. Panting is also a sign of pain so that may be why she is panting more often, Generally an anti inflammatory drug and a pain killer are given at first to see if that will aid the dog but sometimes that does not always work and steroids are needed.
There are concerns to watch for and the biggest would be the loss of use of the rear legs. If that happens the dog needs emergency care.
Until you can get to your vet you can try giving aspirin for a couple of days to help with the pain and inflammation. Keep her well rested with outings for potty only, no long walks, no high 5's or playing. Aspirin is not the best anti inflammatory for dogs as it can cause stomach ulcers so only give for a couple of days tops and see if it helps. Give with food to coat the stomach and let your vet know when you last used aspirin as other pain meds may have to wait until the aspirin leaves the body. Be sure to use plain aspirin and not Ibuprofen or Typlenol type products.
aspirin dosing and information: http://www.petplace.com/article/drug-library/library/over-the-counter/acetylsalicylic-acid-aspirin
I am going to direct you to a site that goes over IVDD in dogs and it will give you some of the symptoms and explain what is happening.
this would be the effects in the lower spine http://www.petplace.com/article/dogs/diseases-conditions-of-dogs/brain-spinal-cord-nerves/intervertebral-disc-disease-ivdd---thoracolumbar-area-in-dogs
this would be the affected area in the neck http://www.petplace.com/article/dogs/diseases-conditions-of-dogs/brain-spinal-cord-nerves/intervertebral-disc-disease-ivdd-%E2%80%93-cervical-area