Ok I haven't had coffee yet. Gliders that chew on their tails are usually from an injury not from distress.
Besides the e collar which IS very much a necessity
and not a choice, what is being done to treat the tail ? Did the vet take xrays? is she on any medication? what is the wound care plan? our of curiosity what is her diet?
I have experience with self mutilating gliders, and the pics on your go fund me is not what I would classify self mutilation. If she chewed on her tail, it was more likely due to pain source in the tail.
A simple tail amputation will not likely lead to her demise. The only risk I can see for having a tail amputation is her age and being put under anesthesia at her age. The older the glder the more risky anesthesia is. The procedure itself only takes about 10 minutes. Does your vet have glider experience? is he equipped to do the procedure?