My dd is 17 months and has never regularly slept through 
She goes down fine, awake and always settles her self without any fuss at all.
She had started to wake about 2am every night so this week I've just left her to moan and she's gone back off on her. But the 5am waking is the problem. She just won't settle. I left her for 45 mins and she went from moaning to really angry and upset. I went in put her back down and she was fine until 7ish.
Any advice on how to crack that waking? Do I just leave her for longer and longer until she stops. She sounds so distressed 