You need to deal with her the way she is. Not the way she is supposed to be, or the way she used to be. Twenty years ago people didn't change so much. It was quite reasonable to expect that somebody comes in after a week without having changed in any significant way. That is no longer likely.
People live between sessions, they do things, they learn things, they run into trouble.
A client can gain even from a generalized program that is intended to match a cross-section of the population. We will probably put her on such a program, if she is interested, after we have handled her major life issues. But we can't expect that we can plan everything in detail in advance. We can't expect that we know exactly how she will behave. It is not so much that you can't persuade people to be treated all the same.