What makes you think that she is purposely doing things when you're not at the store to drive you crazy? Maybe she's just a clueless person who thinks she's the center of the universe. What I'm saying, is that instead of interpreting her actions as an personal attack on you, could it be that she just doesn't know that you guys are supposed to work as a team? Are you supposed to work as a team?

So, I would give her specific examples. The time you decided to do (whatever), really caused me some problems. Here's why......
In the future, I would appreciate it if you would let me have input into this sort of thing. You you can always call me on my cell phone.


So, maybe I'm not getting it. Does she have some sort of seniority over you to change things? If so, then she's sort of your boss.

If she doesn't have seniority, then she's either clueless (I always assume that everyone in innocent until proven guilty) or she is a insecure, power-hungry person who needs to be counseled by her supervisor. That's not your job. Like I said, maybe I'm not getting it.

You have to be specific. If you are emotional (because you perceive her actions as a personal attack on you), you will lose the battle. This is not about emotions at all. It is to come up with a plan to work together and do the best job possible for your customers.