Humidity will indeed be a factor in watering succulents, that is why got to let the plants dry out and do watering at the early part of the day. Victoria did mention the plants are in tiny pots, so drainage is faster. And if I remember it right, Cinta, at times, you do not put drain holes in some of your containers, so water drains a lot longer, so the longer pacing of watering is okay in your set-up.
In Victoria's set up my understanding, it is in tiny pots with drain holes, so just got to water once a week. It will also help to know the orientation of that window where it will be placed. Now if they intend to just put it by the window in an airconditioned environment the interval can be a bit longer, however those plants will surely etiolate, and will grow lanky and weak, especially if the orientation of that window is North. These plants enjoy the summer warm temps with a bit of shade if temps are exceedingly high, with the exception of cacti which truly enjoys as much full sun as it can.
