It is thought that not everyone with coeliac disease is sensitive to the gluten found in oats. It is normal practice to advise avoiding oats initially and if they are introduced again later this should be done with careful monitoring of the condition. My seventeen year old daughter is a vegetarian but seems to rely on cheese too much for protein. A vegetarian diet can be a healthy if it is planned carefully. Anyone who does not eat meat, fish or chicken, should try to ensure that they have a varied source of protein their diet.
Cheese is nutritious as it is a good source of protein and is high in calcium.
However it can be high in fat and is low in   iron. If you eat foods rich in vitamin C with iron containing foods, this will helps absorbtion of the iron from that food more effectively. Foods rich in vitamin C include fruit juice, kiwi fruit, grapefruit, oranges, tomatoes, salad, potatoes and green vegetables. If you are nervous about cooking with beans and pulses, remember that you do not have to use dried ones as tinned versions are just as good. There are some very good cookery books on the subject.