Pretty much what you want in a signature asset -- it makes Dr. Fern more of what she already is, adding a little card draw and the option for quicker healing. The test puts the breaks on a bit, but Carolyn should be able to pass it most of the time in Standard. At higher bag difficulties, you probably want to avoid unnecessary tests due to those nasty special tokens, so this would get used for the reaction ability most of the time, I expect.

This is paired with the less troublesome of Carolyn's signature weaknesses, and is definitely easier to put to use than Foolishness, so most plays will stick with the "box" over the "book" sets.