This study lists the Wahls diet as one of the therapies they are studying. The study is still recruiting patients so it is still ongoing. It doesn't say what phase the trial is so perhaps she has preliminary data or some phase one data and now is moving forward with more patients?
[url=http://clinicaltrials.gov/ct2/show/NCT01381354?term=multiple+sclerosis+wahls&rank=1]Nutrition, Neuromuscular Electrical Stimulation (NMES) and Secondary Progressive Multiple Sclerosis (SPMS) - Full Text View - ClinicalTrials.gov[/url]
As a side note, there a hundreds of other trials going on for MS right now. If you look through there are quite a few trials testing vitamin D, vitamin A, alpha-lipoic acid, different exercise strategies, and diet (granted it is a low fat diet, but still it is diet).
So this idea that people have around here that the ONLY way a trial gets done is if big pharma can make billions on it is just wrong. The system is undoubtedly skewed that way but there is fantastic, non-profit driven research that goes on all over the place.
One example of this is the Immune Tolerance Network. They will only fund research that is designed to treat autoimmune diseases in a curative way - no ongoing expensive drugs are allowed. There is no profit in this - only hope for cure for autoimmune disease. It's not all doom and gloom.