I think one of the the purposes of someone like her would be to guide what the other real witnesses see and report, to be with them, to converse with them, to influence their recall and testimony, so that if someone happens to have seen something strange, she would influence them to change it to fall in line with the approved story by repeating her story and suggesting why theirs may be wrong, etc. I'm sure there's a whole science and training as to how that is done.