Wings are cut to keep them from flying out of their enclosure. It doesn't really have anything to do with what medications have or have not been used on them. You need to ask 1) if they were getting medicated chick feed (were you feeding them medicated?) and 2) whether they've been wormed (and if so, which med was used). I think the most likely scenario is that your remaining pullet has exactly the same thing that killed the other pullet and they either acquired it after you brought them home or they were already sick and the stress of moving them didn't help. I'm not sure why you poured water on her???