My DS1 has only done this once and OMG, after hours of almost continuous screaming I went to pieces. DH ran me a warm bath (at 3am) and I relaxed for about 5 mins with headphones in. DH then gave me DS1 as DH needed to go to the loo. I put DS1 naked on my chest with his bottom and legs in the water, patted him on the back and he fell asleep immediately. I don't know whether it was the water or exhaustion but we stayed in there for about an hour and he didn't stir. When I got out, I put a nappy on him and he didn't wake so I put him back to bed.

Thankfully it was a one-off. Hope your DD has a good nights sleep tonight.