I have no idea how sammy 64 works either. I lock the doors that have proximity alarms and look at the cameras around the office when I hear the voiceline, but no matter what I end up losing to someone I never even saw on the cameras.
She should have a sound cue for when she is nearing the office, check the rooms connected to the hallways into your office and see if she is running through one of them then close it before she gets to the hallways into the office.
