Yes take them to the GP. All you can do about the sleep walking is install stair gates and ensure there are no obstructions for them to fall over
Some children snore more in hayfever season.
However this book is very helpful as well.
He states (page 384) that "impaired breathing during sleep destroys good quality sleep in children. At Stanford University School of Medicine they studied 8 children (seven boys and one girl, ages five to fourteen years) all of whom snored. All eight children snored loudly every night and snoring had been present for several years. Snoring in one child began at six months old, and while the snoring in most children was originally intermittent, it eventually became continuous. Here's how their symptoms were described:
Daytime drowsiness: Five of the eight children experienced excessive daytime sleepiness. The report noted that the children, particularly at school, tried desperately to fight it off, usually with success. To avoid falling alseep, the children tended to move about and gave the appearance of hyperactivity.
Bed-wetting: All the children were toilet trained, but seven began wetting their beds again.
Decreased school performance: Only five of the eight children had learning difficulties, but all teachers reported lack of attention, hyperactivity and a general decrease in intellectual performance, particularly for older children.
Morning headaches: Five of the eight children had headaches only when they woke in the morning; the headaches lessened or disappeared completely by late morning.
Mood and personality changes: Half the children had received professional counseling or family psychotherapy for emotonal problems. The report noted that three children were particularly disturbed at bedtime; they consistently avoided going to bed, fighting desperately against the sleepiness. They refused to be left alone in their rooms while falling asleep and if allowed, would go to sleep in the living room.
Weight problems: Five of the children were underweight and two were overweight.
Overall we have a picture here of impaired mood and school performance, which deteriorated as the children grew older or as the snoring became more severe. Sleep is definitely not bliss for these children. But was this a new discovery? Not really. As I will discuss further, most snoring children have enlarged adenoids, which medical texts written as early as 1914 acknowledged can disrupt sleep and cause behaviour problems."
I didn't type all that out to scare you but as I thought you may find it interesting to read. My children sleep worse if they're overtired and cry out more in their sleep. I think your DD is very tired bless her and struggling. But it's well worth seeing your GP and for them to look in her throat to see if it is adenoids? The sooner it's all resolved, the sooner she sleeps better again, and so do you, as you won't be worrying about your lovely daughter.
My brother had to have his adenoids out due to snoring and he repeatedly kept getting tonsillitis as well. Once his tonsils and adenoids were removed, the snoring stopped and he slept better. I'm not saying it is definitely adenoids but it's worth seeing the GP and I typed that blurb out from the book as I thought you may find it helpful, although there was probably more I could've typed out but I need to check on my DS
Hope it all gets better soon anyway x