I hated Barron's! Wayyy too much art that was not necessary for the test. It was not even interesting. The information it did have is useless when it comes to writing the essays.
For a review book I highly recommend REA. It is not only entertaining and instills an appreciation of the art, but the material covered was actually on the test. The passages were extremely helpful for writing my essays. I got a 5
I did read the Annotated Mona Lisa and I skimmed the Annotated Arch. The Mona Lisa was not nearly as helpful as the architecture centered Annotated Arch. The things in the Mona Lisa book were already covered in REA and in a better fashion. The Annotated Arch I skimmed the night before the test and the one piece of architecture I looked at was what the essay on the test was about!
So I would get REA and the Annotated Arch. If she is self studying, go ahead and get the Mona Lisa, otherwise this will suffice!