OMG, I didn't realise she was up all night. That would really do my head in. Have I got this to come, do you think?
Would bribery work with your DD? Maybe a new bedtime routine? Starting earlier perhaps? Is she more tired from something now (apart from the staying up all night, that is)? Has she started something new that might have unsettled her?
I don't know what to suggest, I know that when my DD is overtired it takes her longer to get off to sleep but she's never been up all night unless ill. Maybe you should substitute her after dinner coffee with a grappina, no?