This is going to be one of those 'the devil is in the detail' situations.
So...
"Her night time needs is one hour routine after the cutoff time"
There is no strict 'cut-off time'. 11-7 is the standard time that they indicate by 'night'. However, if your household doesn't shut down until after DD is settled, they can argue that it is still 'day time'. So, you can have different scenarios:
Child goes to bed and settles at 8pm. Parents go to bed at 10pm. Child wakes for one hour between 11pm and 12am. This is night-time care because the household had shut down and then the child woke and needed care.
Child takes until 12am to settle. Parents tend to child's needs, then lock up and go to bed once the child is definitely asleep, for safety. This can be regarded as day-time care because the household hasn't shut down.
Equally, if a household would only get up at 7am routinely, but the child wakes at 5.30am and can't be left unsupervised, then the parents can argue that this is 1½ hours of 'night-waking'.
(LegoAcupuncture you should contest that, btw. The decision maker's handbook gives the specific example of [iirc] a farmer whose usual start time was always 4am, so he still wakes at that time. Because the carer's usual wake time would be 7am, the 3 hour difference must be regarded as night-waking)
"She also requires a extra hour through the night because she needs a happy change which requires the same one hour to be spent putting her back to sleep. for the above reasons other than this about 2 nights a week she wakes and wanders."
This confused me a bit. Are you saying that she needs her nappy change and/or wanders for 2 nights per week? Or are you saying that she needs her nappy changed every night, and then additionally she wakes and wanders 2 nights per week?
To get HRC, the night waking component must be on at least 5 days out of 7.
The nappy changing may depend on your description of it. If you say 'I need to change DD's nappy and settle her again, this takes a hour.' the DM can argue that a) a child of 3 can often need nappies b) they may be suspicious of a nappy change taking an hour. To justify this as care 'over and above a normal 3 year old', I think you'd have to explain why you have to change the nappy mid-night. What would happen if you didn't. What happens when you do - what steps you have to take to settle her. How that's different than normal children, etc.