there are two types of mange. sarcoptic (spreadable to other animals and humans ) and demodex ( non-spreadable to either ). all animals carry the demodex mite . sometimes if the immune system is low, stress can trigger it into a breakout. usually it will happen before they are a year old. both require immediate treatment. i would keep her away from other animals and people until you can get her to the vet first chance. both types are treatable and cure rate depends on catching it early.
Yes, Your vet will also do a few simple skin scrapings to detect which type of mite it is. Don't feel bad, many of us here have been through this too. My Chi had the Demodex type & a thyroid problem when he was around 1 yr old. It wasn't contagious of course, just made me feel so sorry for him....he looked so moth eaten. He was completely cured of it & did fine. Let us know what your vet says! :)