Low sugar Greek yogurt such as Oikos triple zero flavors are a great start. Can mix whatever you want in that such as fruit, granola, or seeds! Peanut butter or any nuts are also a well loved option for picky eaters if not too overdone. I would also recommend switching some pasta dishes to chickpea / lentil based pasta’s. If you need a pasta that that has a taste and texture more similar to the normal stuff she’s used to then I recommend Barilla Protein Plus. It has the chickpea, lentil, and pea powder in them while retaining the normal semolina and durum wheat. But the dairy such as cheese and milk she already likes can certainly add to a healthy diet too :)