Well I'm probably no great help, but I've had one awesome easy sleeper and 2 non sleepers. In my experience if they're not going to sleep, they're not going to sleep. I have tried everything between the two and just end up riding it out. It's not you, it's just that they're all different. DS1 would sleep if I took him to bed with me though. Will your DD sleep with you? I'm a believer in it's not who's sleeping where, but who's sleeping! It's my only suggestion for you sorry. Worked for my DS1 but not even co sleeping gives me a full night with DS3.