In the state I live in, Ohio, only Registered Dietitians can provide food recommendations and meal plans. Please be sure you are not opening yourself up to liability issues by providing this information per your states requirements.
That being said, whether you are able to answer this, or you have to refer out, you can always defer back to the Food Guide Pyramid and encourage healthy eating from the main food groups, focusing on fruits and vegetables.
When you mention her culture possibly posing an issue, I’d challenge you to find the healthy components of a Chilean diet: foods that grow there include grapes, apples, pears, onions, peaches, garlic, asparagus, beans, and due to the coast they have a lot of fresh seafood available. There is plenty she could make that is high in nutritional value from these items! Taking someone out of their culture is setting themselves up for disaster; you have to find a way to keep it as part of them, or just as crash diets ultimately fail, so will her new meal plan.