We're going through that at the moment, OH allowed Maike into bed in the mornings when she started barking after her 5am wake-up call and this turned into her barking in the night, in the morning... I haven't had an uninterrupted night's sleep in 3 weeks, and suprisingly enough instead of barking to go toilet once at about 4am she suddenly wanted/needed out at least three times.
Well, thank goodness for thick walls and slightly hard-of-hearing musician neighbours as we just decided to let her bark. 40 minutes yesterday at 4:30 in the morning but then she was blessedly quiet. Tonight I slept alright (night nurse and earplugs ) but at about 7 there was a dog in the bed again! I asked OH what was going on and apparently "she's been so good, she only barked once at 4am for about five minutes and then at 5 for five minutes!". Oh well, that's alright then!
I reckon it's going to take another night or two with earplugs and just letting her get on with it to stop the racket at night but hopefully by then the bad habit will have been exorcised.
I'm sorry Darcey has started up again and if you are in a position to do so, maybe sleeping with earplugs for a couple of nights might be the way to go. Once she realizes no one is reacting to her crying she might stop. Leave her with an extra blanket to make sure she's not cold so you can sleep without worrying.