just a couple things.
solids are suppose to add to her diet, not replace. she is supposed to be getting the same amount of breastmilk/formula, then add solids to it. you need to make sure she is getting that first as her main nutrition should be coming from the breast or bottle. if she is filling up on the solids first, there wont be any room left. they now recommend solids not starting until 6 months. your daughter only being 7 months and having that many servings already is too much. just remember that the breastmilk isnt a drink, its her entire nutrtion.
second thing- dont offer any water, esp if you are concerned with her not getting enough breastmilk. when she is thirsty, offer her breastmilk. breastmilk is some crazy percent of water so any hydration can come from that and she will get the added benefits nutritionally. there is no need at all to give a breastfed baby water, and it will fill her up when she should have had the breastmilk.
for your lessening production, you could pump more on the weekends, or feed directly from the breasts more on the weekends. also you could pump more when you are home. like if she goes to bed at 8, you could pump right after you are done feeding her, then again later in the night. any added stimulation will help, but having her is the most effective. also try fenguneek. many moms swear by that stuff. as for the supplementation, im not sure. if you give her formula, you are telling your body "i dont need any more now" then you make less. but then you could make less again, and start the cycle more and more as you keep lessening. if i were you, i would do everything i could to try and gain milk production. if absolutely nothing worked, i would add the formula, but i really think your milk production will rise if you take care of them.
also, what about your period, did you get it yet or was it around that time. periods cause milk production to temporarily lessen. make sure you are also hydrated enough, esp being so hot in the summer. if you arent getting enough liquids, your milk would be less.
good luck!!!