"I have a friend with serious autoimmune disease. She has bad breathing reactions to most smells and odors. Will an oil or topical with a high CBD content give her any relief ?"
There are many types of a autoimmune disease but supporting the immune system with high CBD cannabis does tend to stop the inflammation and regulates the immune system especially if treated internally with a tincture of high CBD/ low THC as well as the topical salve applied externally. The fact that your friend reacts to smells and odors makes me wonder if your friend has a predisposition to migraines which will make your friend chemically sensitive and the odors can cause depression.
Autoimmune disease will also manifest if the person is vitamin D deficient (vitamin D is a hormone, not a vitamin) if the vitamin D deficiency has not been recognized and treated appropriately.
It certainly seems worth a try to utilize high CBD/ low THC and correct vitamin D deficiency and your friend maybe well again especially if you also eliminate toxic exposures.
Good luck, this is a quest worth doing.