Be prepared also for her -- after she's done being livid/pissed -- to actually be INCREDIBLY NICE TO YOU.
And then switch back to mad-as-a-hornet again.
And back.
The "acting nice" can happen as soon as the next day, or maybe a few days or a week later, but it happens more often than not, and LBSs are always stunned by it (I know I was!).