Sounds like things are going perfectly! THe hardest thing for me has always been letting Severus hide out for the time he's blue. I always would freak out and disturb him just so I could have some peace of mind. Now I know he just stays hidden away as long as he needs to. I've used sphagnum moss before. Just make sure you wring it out really good and don't leave it in for too long. I don't use the moss anymore because my humidity is usually anywhere between 50-70%. Previously I put it in his cool hie because it was easier. I honestly don't think it makes too much of a difference as far as where in the tank you put it. If it humidity ever drops and you want to increase the humidity overall, I previously successfully used a damp, very well wrung out, hand towel and laid it over half of the tank lid. My humidity drops like crazy during the winter. It'll go down to about 30% during the colder months for me.
Make sure you check her once she's shed. Get her shed out of the tank and make sure the eye caps and tip of the tail are there and not still stuck on her. If you find she ever has a little leftover skin on, don't fret. That happened once to me with Severus and a put a wash cloth in a separate bin with a little water and that help to rub it off. I ended up having to rub a little with the washcloth myself though. There's a sticky thread on bad sheds that's very helpful.