I am getting my tape measurement handy so I know I am not hallucinating. She's napping again after playtime - on my favorite chair, my working computer chair. I've been cast off onto the dining chair. Hmmm.....
It takes a lot of energy to build new cells in the body, no matter what type of critter you are discussing. Babies are constantly growing, but during sleep, more energy is available to divert to the production of new cells.