Are you EBF? If your LO just got over a wicked illness, try not to stress about her still taking a DF. There's nothing wrong with a little extra hydration. You could try doing the DF with a bottle of BM, and slowly cut it back over a week or so. That way it wouldn't be a dramatic end. Although I had to switch for formula at 7 months, I started with 8 oz and then every other day I reduced it by an ounce. At the same time, I upped the amount of formula and/or food DS received during the day, so that he wasn't losing any calories. That's what I would suggest.