Tell her to only regularly eat the three standard meals (nothing in between) and make certain there is no sugar (including fructose - all fruit) in any of what she eats or drinks in a balanced diet. That should bring noticeable results within five weeks - keep it up. You don't say how much weight - if she is obese, not to mention morbidly obese, then cutting either lunch or dinner out altogether may be called for. She should make certain she drinks enough fluid throughout, plain water is best (straight from the tap, no need for bottles). She must not go back to previous eating habits, eating too much, after the weight is off because then it will simply return.