They also, which I hadn't seen before, come with a section of the back board cut out to make room for skirting boards, so you can have them right up to the wall (although I had to make the cut-out section bigger to fit my skirting).
Does she own the apartment or is she renting? If she owns it then it might be better value to get a chippie in to put in a full wall white MDF shelf unit or something similar, to maximise the amount of books she can store.