be honest, tell her you are going to stay on top of it and will hound him to have everything available so the audit can be done in one stop. BUT you are swamped with tax season and would like till the end of April. I never had an agent deny this. besides if you are in a major area like i am the agents calendars are full for at least a month in advance and you will get your time.
an alternative is to have the first meeting, give what you have and then you will get an request for additional info which well take a few weeks to get and at least a month for you to answer