I have never left my boys to cry until they pass out from the exhaustion of crying. I have left them to grizzle & maybe cry for 5mins here and there. But all my Mother instincts can't let me leave them any longer. Saying that I do believe it takes patience & consistency. I'll leave them for a minute or 2 then go in, lay them back down and leave again. I'll go back in 5 or maybe even less if their really upset. Lay them back down say goodnight & leave. The first night or 2 I'd be up and down like a yo-yo but eventually they learn that it's sleep time, but Mummy will always come to reassure them. It's a tough one. I understand parents who try it when they've tried everything else. Max sleeps ok most of the time but he still has the odd night where he's ended up in our bed because all else fails lol Don't pressure yourself too much about where she's sleeping. As long as your both getting some sort of sleep!