i haven't found it to affect my supply - DS has usually only ever had a couple of bad days & has then been back to feeding normally. as esme says, your supply will balance back out (if affected) with a couple of days of more regular feeding once she's feeling better. i also found that sometimes my DS prefers to have some water over a feed (maybe because he can sit up to have it rather than lying? not sure) & while that freaked me out a little, i guess it's good that they have the fluids one way or another - esp if it's warm.

hope your DD is feeling better soon