Re: Question re: time-outs
I'm going to put it out there and say I can see why the babysitter and her husband acted the way they did. Do they have kids? My lo isn't as old as yours, so not up developmentally with what's normal at that age, but I could see trying something like this if you weren't sure if the child really had to go or not. Maybe it wasn't appropriate since it wasn't her child (It was yours!) but sometimes as we struggle to teach and parent we try stuff that in hindsight wasn't such a good idea. Not saying it was a good thing to do, just saying it was a tough spot, and I'd probably grant some grace.
Also, regarding the potty to potentially get out of timeout or bedtime, I would get one of the small kid's potties. That way, if she really has to go she can. But she doesn't get to leave the timeout location or her bedroom since the potty is right there. Something to try :-)