I recently lost about 50 lbs on Weight Watchers. She can follow the points system without actually joining. The equation is listed in their patent - which is available to the public. It translates at this:
Points = Calories/50 + Fat/12 - Fiber/5. Fiber is capped at 4 g in terms of calculating points.
Given she'll be exercising intensely, she'll be earning another 6 points a day on top of the 20-25 points she should be eating to lose weight. On days that she doesn't exercise, she should stay within the 20 - 25 point range. I was a sloppy vegan for years (5 to be exact) and put on tons of weight. I highly recommend WW because of it's practicality and nutritionally sound approach. It's really helped me become a "good vegan" and I enjoy healthy cooking. Recently, I made Veggie Tempura and the taste of oil made me gag. Let's just say, this was not always the case.