Are the milk and yogurt full-fat? Definitely not low-fat or skim, especially at this age - they need all the good fats they can get.
Have you tried avocado? You can mash it up alone; we added some olive oil to it. A small dollop of butter or coconut oil in the cereal is another way to add good fats to the diet as well. Is she eating any meat yet?
At this age she can still do with plenty of breast milk, but if she's waking that much at night, a supper with more protein and/or good fats can help keep her fuller longer.