I have read conflicting reports, some say don't place water in their enclosure after they eat because Rosys have a tendency to drink too much water after they eat which could cause regurge, some say keep water in the enclosure all the time.
This is what I do and other may disagree but that's ok, it works for me, I keep water in my Rosy's enclosure all the time except, I take it out the day I feed her and replace her water dish the day after feeding day and I have had no issues with her so far.
I do however place a humid hide in her enclosure when she goes to shed.