Oh that's great that you have a water pic already, it will be so much easier for
sozlet to clean in between the braces.
School lunches consisted mostly of soft whole wheat breads with peanut butter and jelly (she loves that anyway) and I cut up strawberries into tiny pieces and other fruit as well, so she could just pop it in her mouth with little chewing; lots of bananas too, and that ramen cup-of-noodles worked well too. Left over spaghetti was always a hit, still is, and I cooked a lot of vegetables that were soft after cooking - summer squash, eggplants, etc. and nothing crunchy like red peppers, cauliflower (although I made mashed cauliflower which was good), broccoli gets really in between the braces too.
It's trial and error, depending what sozlet likes, but I kept it simple. Plus sozlet will let you know what's workable and what's not.
Since pizza was a bit difficult to eat, the occasional hamburger and fries
was a better choice.