Hello. Moderate physical activity is actually good for health but it should not be severely. As far as the diet is concerned till her to take daily twice one glass of milk, egg white, fresh raw sprouts. Tell her to have apples, citrus fruits, nuts, green leafy vegetables. Certain pergnant woman has craving of chocolates, ice cream, certain foods which is quite natural.If you are a non vegetarian, then a meal which is not spicy and not oily can also be taken. Tell her to do some breathing excercise like pranayama and meditation to keep in check of stress levels. Make her as comfortable as possible. If you are not satisfied kindly consult a dietician for further management.