My sister and I are co-owners of mom's bank account trust, is she allowed to take out money and move it to another account without my consent?

Our mother just passed few mos ago and my sister and I are co-owners of the bank account trust. She is Executor and I am sister and co owner. She split some money to us already but not all of it. She transferred balance to another bank account without me knowing so I cant see what she does now. Is she allowed to do that without my consent? Thank you