4 women in a studio that you know and get along with wouldn't be a problem. I would probably check to see if one would be willing to sleep on an air mattress or camp cot. They also need to be women who control their stuff well. I spent this week with a 17 year old that I had to speak to about keeping her stuff in one spot rather than all over the floor...in front of my suitcase.
Either way, except for OKW, you have to put the sofa bed up and you only have one bathroom. That's why I'd consider opting for a unit with internal hallways (BWV, BCV, VWL). It'd be possible to get to a back up bathroom in reasonable time if your need wasn't urgent. First floor VWL is probably the best for this trick. SSR would be okay if you are near a pool like in the Congress Park area.