Hiya!
We stayed in a fairly basic Forest Lodge, and it was fine.
My boys are 5.5 and 7.5, and there's loads of stuff you can't do until you're 8 So your dd should have lots of choice at least!
We booked them in to do a kids club at 12.00 on the day we arrived, which worked quite well as we could then look around and get our bearings, and have a relaxing lunch. They got a (fairly basic) packed lunch with the kids club too. DS1 enjoyed the club, but ds1 found it rather boring.
There were long queues for the bikes earlier, so we went down at about 5.30 pm when it was very quiet. It was dark then, and the boys enjoyed the adventure of going out for a walk/ride with torches. (Don't forget your torches!)
Personally I found the waterworld a bit crowded and noisy, but the kids loved it! We went at least once every day.
I found the supermarket quite reasonably-priced, though actually we had shopped before we arrived. But - as anticipated - I found the 'eateries' overpriced and very dubious quality and service.
What else? The boys loved going to the Rangers Lodge and watching the red squirrels and birds feeding. We enjoyed walking and riding along the forest trails and seeing loads of birds you don't normally see, as well as rabbits and red squirrels.
That's all I can think of right now. Have fun!