I had the same problem...
If the client wants to write away her pain, she can do that all by herself for free. It won't matter in the least what the work looks like when she's done. It's good therapy that does work to some extent, but does not work totally. One of the things I have found extraordinarily useful in using my writing as a form of therapy is the sentence-completion exercise. A little work in that area produces tremendous results; I tell you that just an aside and a suggestion.
If she's in such great pain, where she's even having a hard time speaking about it, she might need some professional help to work through some of it and be done with it before she'll be able to concentrate on the complexity and enormity of writing a book. Is she well enough to work with?
Writing about her pain isn't going to work for publishing. The plain truth of it is, no one cares about anyones pain. Everyone's got enough of their own.
The pain must be made a purpose. There must be a story; a beginning, a middle, and an end. A happy ending. A new beginning. A triumph. An understanding. A theme. An answer. Something like that.
I've got plenty of pains to write about. When I started writing all my pains, it got so boring I quit writing. It was pure drivel and absolute bullshit. It sounded like I was whining. There was no point to any of it. Nobody loves a victim. Nobody loves a whiner. Nobody wants to read about it. Nobody cares.
But I did not want to whine. In fact I wasn't whining. I wanted to tell my story. But I didn't know how.
I had to create a purpose, a theme, a reason for telling it. I had to find a way. Since life has no meaning outside of the self, since life has meaning only to the self, to the one who puts purpose and meaning to their life, that tells you everything you need to know about what others like to read. They are looking for meaning and purpose to put to their life. They want to know what the writer has found and what it will do to help them in their own life. They want answers.
The pain can be used to demonstrate, for example, the incredible odds she had to face on her way to what she wanted. Which is a good question to ask of her to start with. What did she want? To be a ballerina? To be a karate expert? To be a Kindergarten teacher? To find the meaning and purpose of life for all mankind? To find god? To conquer her own ego? What did she have to conquer and what did she have to give up in order to get what she wanted? Did she forget about what she wanted at some point and take a u-turn that worked out well for her? What did she want? Where is the struggle? Where is the conflict? Enduring pain isn't struggle and conflict. Violence is someone doing the violence and someone getting it done to them. Nobody cares about any of that. It's not going anywhere. They can watch all the bad news on television all day long. No need to make the effort to read a book about it.
I had too many personal problems to work through before I would be able to tell my story. Too many unanswered questions. So, I had to forget about writing the story for a long, long time, and get the business of solving the personal problems and answering all my burning questions in order to have what I needed to get on with it. Now, the words are flowing so fast that I can't keep up with it all.
I've done a ton of research on this. It's starting to make sense. There's a ton more to it than meets the eye. There's a lot more to it than just talking about how many times you got your ass whupped. That's about as exciting as reading the memoir of a businessman who has done nothing but fail his entire career.