I have 3 children and pregnant with my 4th. I am getting a little bit desperate for a full nights sleep, as they have been in short supply for the best part of 4 years what with pregnancy insomnia too 
DD has never been a 'good' sleeper, we co-slept until she was 18 months, we now lie with her until she drifts off, can be 10 mintues, can be an hour.
She has phases where she does sleep all night but mostly not. She wakes up and crys but won't say why she is crying! Sometimes it is because she needs a wee just go then but mostly I think she wants a cuddle, even then she sometimes will keep waking! What I am finding hard is that she will lie in bed calling out/crying but not actually come to our bedroom.
We have tried bribery, talking to her about it. Help please, we're knackered. 