My DD is 5 mo and every few weeks she will suddenly start with screaming when she has gone to sleep. It's a cry we don't hear at any other time. When we go in she is still asleep but she keeps crying and screaming. If we pick her up it takes a while to settle her. Are we right to pick her up and cuddle her if she is still asleep? Or is it best to leave her. It's very upsetting to see