There will probabaly be very varied answers to this. When my kids were in cribs, I would put them in the crib as a time out if they had to. When they were that young, it wasn't very often, but it was the only safe place I could place them and leave to make the point. Once they were in beds, I would put them in their room...I really love the Love and Logic parenting style. So, I can say to my 3 year old "oh, this is so sad" and take him to his room and he will stay there until I get him. I can also just tell him, "no, that is not acceptable, go to your room" and he'll go. That being said, I can also be in a store, restaurant, etc. and tell him to have a seat, he's in time out and he'll stay. So, it's not always that they need to be in their room, sometimes it's just that they need to stop or be removed from the situation. So I guess I'd say you can use the cot, but if you dont' have to, you may want to reserve the cot for nap times and bed times to it's not associated with anything negative and just do time out in a corner or room. The key is always consistancy, so wherever you choose to put her, you take her back again and again until she stays there.