You may control only your character. You cannot post that someone’s character did something or said something without having that player's permission beforehand. This includes impersonating another character, or determining whether a spell your character uses affects the other character. An example of this would be: Correct: John asked Helen to come along, hoping that she would follow him to see the Squid. Incorrect: John asked Helen to come along. Helen replied with a yes.
It seemed fine with the girl, so Rowena walked up to the broom and picked it up.