When you hear her laugh check the room to the right of the office. If she is not in that room you're safe but if she is there you'll have to close the door until you hear her laugh again.
The kitchen. I've tried night 6 a bunch of times and I'm pretty sure her pattern is the same, which she laughs 3 times total and the third one always signals her to be in the kitchen until 6 am. So far it's been consistent.
