Starting with low dilution you could try Plai, Sweet Marjoram, Lavender and possibly Ginger for joint pain. Rosemary and Black Pepper are stimulating so possibly not best if she is really fatigued, although if the fatigue eases they may be of use. Basil in low dilution can be a useful tonic and she could try any of the citrus oils as they are uplifting without being profoundly overstimulating - I'd suggest Lemon or Grapefruit ideally organic.
Geranium and Lavender are also balancing. If your friend feels the cold she could also consider warming oils such as Nutmeg which can also be useful for pain as can Cinnamon Leaf and Clove Bud although all three of these have to be used in very low dilution as they can be irritant. Ginger is also helpful here.
It may be worth her seeing a professional aromatherapist who can make her up a blend specific to her needs. In my experience conditions such as lupus need a thoroughly holistic approach so reiki or crystal therapy or something similar in conjunction with aromatherapy would be of additional benefit.