reading your post, i would strongly suspect the frequent waking is related to the eczema - if she scratches to the point of bleeding every time she wakes, it's possible (probable?) the itch is waking her - and she needs you to distract her/comfort her back to sleep. when you move away it would take her out of the deep sleep and the itch would irritate her again... i can't imagine sleeping through a severe itch myself, so i assume it would wake her up too. i would push for as much help as you can get. is there something the gp can offer that will help reduce her discomfort, particularly over night?

i don't know much about it at all - but your mention of the severe itch/scratching at every wake up just screamed at me that it was related. poor possum! (and poor mummy - i know how much sleep deprivation screws with you!