It is telling that she doesn't call him Anakin.
Master Skywalker, yes, and Sky-guy when she's scared or uncertain about her place by his side, covering up her nervousness with friendly joking; much in the same way she has seen Master Kenobi tease his former padawan. But she is temple raised, and it shows. She treats her new Master like an equation, testing each variable personality trait against Anakin's approval.
It's not really her fault. Despite her tendency towards passion and her flair for the dramatic, she was raised in the sheltered halls of the jedi temple. She has been trained to be calm and objective; she has been taught that all problems have solutions.
Anakin, of course, knows better. So does Master Kenobi. Obi-wan is, while often hopeful about the future, is as much as a realist as his former apprentice. It is just one more thing that has made them unique within the jedi order.
Asohka Tano, for all her self-possession, cannot see the world around her as her Master sees it. And what's more, there is no way for her to bridge this gap in understanding. This is why she will keep adjusting her behavior, shifting from obedient to rebellious, to receive a small smile at her antics. This is why she will continue to hang out with the clones and quip witty one-liners in imitation of his barbed jokes. This is why she will not know anything beyond the superficial; nothing about her Master's past or present, dreams or desires.
This is why Anakin will remain Master Skywalker and, occasionally, Sky-guy.