I agree that she needs to be brought into work gradually. That does not mean that you should accept pissy behavior. If you ask for a walk, make sure she moves out immediately. Do not accept a slow or insolent response. Give her one nice "ask", then a "tell", then smack her roundly and get the response you asked for two secs ago. Now@!
And, forgive me for saying this, but jsut becausde you got a new saddle does not mean it fits her. Pain should always be the first thing to consider in cases of pinned ears and other kind of bad behavior when being asked to move out. She may have need of chiropractic work.
Can a more experience rider get a better response out of her?