Handselling. Not for the hesitant or unassuming.

Intro to Advanced Bookselling, Sec. 1
Instructor: Paul

A customer asks for Kate or Lisa, hoping that they can recommend some books for her.
She wants something piercing but quiet. Thoughtful and...well...something that Kate or Lisa would want her to read. But...

Kate and Lisa aren't here today.

Your objective is to assume their reading tastes (without giving the impression that you might be stepping outside of your own comfort zone), recommend books to her that they would recommend, were they here (but not books that they already have recommended to her), and, in order to make this challenging, get her to buy two books that you love, but that they would not recommend (making it seem as though the books are completely in line with what they themselves would choose, in context of the other books).

In summary:
Without a moment's notice, get inside the head of a stranger and two co-workers. Give her what she's asking for (what your co-workers would give her), and what you think she should be asking for, (books that will surprise her and push her outside of her expectations).

Go.