Looks fantastic! I have mine in a 18X18X24 Exo-Terra, with a medium Exo-Terra waterfall for a constant humidity of mid-60's to mid-70's, with a spike of 80ish after a late evening misting. Cresties love tall enclosures and vines to hide in. However, it is also important to provide some horizontal perch for them to relax on. Some people believe that sleeping upside-down on the glass can lead to the 'floppy' or 'dead' tail condition in which the muscles at the base of the tail basically stop working and their once near-prehensile tail just sort of flops back and forth like a dead limb.

You can get a Repti Hammock (made by ZooMed) in various sizes and stick it in one of the back corners behind some vines. That works well. You can see a picture of it here: Repti Hammock

Another thing to remember; don't let the temp get over 80. Most people say 82F is the highest, but I prefer 80 just to play it safe. Prolonged exposure to temps above 80-82F are fatal.

If you want to provide a small basking area in one of the upper corners of the enclosure I'd recommend a low wattage (25-30) ceramic heat emitter. I recommend a CHE because in my experience heating/basking lamps kill humidity.

Don't forget to clean the waterfall at least once a week, and to clean out the enclosure at least once per month. A fantastic cleaning agent you can use for this job is "Healthy Habitat all-Natural Cleaner/Deodorizer". It is also a mild disinfectant, devoid of toxins and fully biodegradable. It comes in a convenient spray bottle, so you can just mist out the empty enclosure and wipe it down, then wipe it clean with a water-damp washcloth. You can also use it on the vines and whatnot. (Works great for your BP enclosure too! Some harsher cleaners, like vinegar, will damage the aquarium silicone over time.) See a picture of it here: Healthy Habitat Cleaner

One thing I would caution you to keep an eye on; that substrate you are using. Some people have reported that when lunging for crickets the cresties can get a mouth full of the bark. Depending on the size you are using it may cause issues. The professional Crested Gecko breeders I know don't use anything other than paper or simple paper towels for their animals. I see that you are going for a more 'natural look', and I am totally into that look too, but after some thought I decided that a simple layer of brown parcel paper was good enough. It is also far simpler to clean every month; just roll it up and toss it out. The brown is 'natural' enough looking for me. I put a few stones in each corner of the cage to keep it from rolling up due to humidity over time.

I hope some of my thoughts have been helpful! Again, kudos on the great setup and wonderful new pet! They can live upwards of 20+ years, so your daughter may have a best friend for a long, long time. hehe.