You might want to ask your friend whether she would feel comfortable passing symbols to you. I know that for some the idea of bypassing a more traditional teacher/student situation might be uncomfortable or seem incorrect. However, it might also help her to believe that what she is doing is very powerful.
My teacher recommended only one book to us, and said that there were many others that she didn't agree with and that it wasn't necessarily important to read. I am curious myself to read a bit and will try to find the book she suggested. This is it: