You might want to consider pine bark for the pignoginal( anti-cancer, antioxidant).It will help the healing of the gut and will assit the GSE and the Black Walnut in your daughters healing process.
It depends on the type of starch. Bananas are fine, potatoes are not, white rice no. Long cooking oatmeal is good. I would not avoid the greens for more then two weeks and I would consider the yellow veggies (squash).