I think maybe you just need to combine the book clue and the map clue back in her office.
hmmmm, i just get the "can't make deductions" from steve when i combine the book, the map in irene's office. and all combinations of the below clues and bag items.
x Behind Dad’s desk is a world map
x The entrance to Dad’s real office is somewhere behind his desk in LotF
in dad's office the map and book get me "I couldn't find a way to use that there."