This spring/summer will be first time DD is in a bed. I am concerned that she may climb onto window sill and fall out of the window when alone in her room. She is three and sensible and not particularly lively, but keep having what if worries. What precautions if any do you take? Would a 3 year old try to climb out or do they have a sense of safety? In summer she will have to sleep with window open as it can be very hot.