Basically, lupus is an autoimmune disease that mainly effects connective tissue and blood vessels. However, it is easily improved from a holistic viewpoint. I know little about it and wonder where to start. It sounds like she needs a fresh way to look at this. If this is that far gone, there may be nothing that can be done.
Conventional medicine is best at prolonging the agony.
If I knew what part of the country she is in, perhaps I could recommend someone personally where you could start finding a professional who would be willing to see her in consultation. Philosophies like Naturopathy, Chinese Medical Practitioners, Ayervedic Practioners, Anthroposophical Physicians, Homeopathy, and the like, would give her that fresh perspective. The only thing that could be hurt by them seeing her is the egos of the current physicians who would sooner see her die than allow a competing philosophy be found to be successful. I get a lot of flu and colds,some benefits are being achieved with echinaca. Interferon looks like something to avoid with all it's side effects.