If she can eat good proteins and get away from the carbs...she may not suffer the mania as much. I know my son suffers mood chaqnges if he eats to many carb...infact right now he only gets carbs from veggies and black beans and lentils and is stable...this is do to insulin resistance, which can be corrected over time...I use to suffer this too..I was never on any meds...but just to let you know even being off or on meds this can occur with to high carb diet.
Good Luck to your friend.