How come Makosi knew exactly where the diary room was so soon after coming into the house? After all it was only ten minutes after the last HM entered the house. Later Mary was still wondering where the diary room was so it mustn't be all that obvious. As soon as BB did the announcement Makosi ran for the diary room seeming to have no doubts as to the location of the room or the layout of the house.

Or am I just paranoid..?

They are probably shown house layout plans nowadays in advance.

Or she scoured the room and saw it, it's probably the second place I'd look far (seconded to the loo!)

She probably noticed the flashing blue/red eye on the wall there...