My son is heading 18mths & around 27 Oz/day.
I guess yr daughter has already cope with 52oz/day & it's hard to reduce immediately. If I were u, I will reduce little by little.. i.e. 12.5oz for few days then 12 oz for few days, 11.5 oz, 11 oz......and gives her time to adjust. I have heard baby drinks too much water is harm but I forgot the standard(I am sure 52Oz is already over the limit).