Other causes of cold extremities with bluish discoloration are hypothyroidism, anorexia
, Addison’s disease, adrenal causes
like pheochromocytoma, anemia, Buerger’s disease, chronic fatigue syndrome and Raynaud’s disease. Raynaud’s disease is a disease of the blood vessels in which blood can't get to the surface of the skin and the affected areas turn white and blue. Please discuss these possibilities with her doctor.
Hope this helps.