The problem with lupus or any other autoimmune system is not that the immune system is weak, it is misdirected. Cause is still debated but is thought to be a combination of a set of genes that predispose the immune system to misdirection and then some sort of a trigger that produces the symptoms. The last thing needed is an amped up immune system. Many of the current treatments suppress the immune system which creates another set of problems: increased susceptibility to infection and cancer. Newer treatments approach it differently but there is no single treatment that works for all cases and suppression is generally the first line of treatment particularly for severe cases.
Coconut oil has been purported (in the Philippines and more recently the western world) to have health benefits for centuries as well as an anti inflammatory effect. Like all holistic treatments there is little science to support the claims of those trying to sell their treatment. I would personally not consider taking coconut oil a risk unless the patient relies on it as a primary treatment for a serious case of lupus.
Make sure your daughter is being seen by an experienced rheumatologist who is familiar with treating lupus. If she has dietary or other general health problems those should be addressed as well through diet and lifestyle changes coordinated by her doctor.
MCTD (SLE Lupus, polymyositis, scleroderma). Diagnosed 2005. Kidney, liver, GI tract, dysphagia, raynauds, barretts esophagus, quadriplegic in 2005. Recovered and now active in downhill skiing, golf, hiking. Meds: amlodipine, benezapril, omeprazole, potassium, folic acid, vitamins, maxide.
Remain Optimistic and you can overcome.