Should i be concerned if my great grandma has calciphylaxisis she going to die?

This is ominous: This may be time to say good-bye. Ultimately it is her choice, but with this severe a metabolic derangement in an older person, quality survival might not be the most likely outcome. Cherish the good times; especially, she or her health care decision-maker must have accurate information about likely outcomes of various choices, including "comfort measures only.".