Things to do with her formula are, very obviously, cereals which is what we do regularly here (mix it together instead of giving cereal alone and milk one hour afterwards). And cereals would mean rice (constipating), corn or millet (the last perhaps also constipating as very high in iron). Perhaps you could mix them with boiled and pureed carrot, and potato, or add formula to such purees, making a firm pure not a liquid one. Some fruit is not acidic and can be tried, like pear, apple or peach. If baby has trouble with it, then discontinue. I know that orange, lemon, kiwi or tomato are definitely a no-no, and I know because I,m a chronic sufferer or reflux (hiatal hernia). Doctors told me to avoid citrus, tomato, coffee and tobacco and, other than that watch out for what gives me that hearburn feeling as it is a very individual thing. In my case, it is chocolate and mint (separately or together, if together it is like a bomb, I love after eights but....cannot take them). Garlic, pepper, chiles, curry and other hot stuff very bad for others, but not for all.
So, watch what disagrees with her. I really thing she is far too little to try to introduce meat or (even worse) fish, which can be made with a mild white sauce made with formula, but that should be left for later, at 7 months, not now.