This is a very common phenomenon, that whatever one doesn't like or doesn't accept about somebody else is really what one does like or accept about oneself. One can't really change it in the other person, but one can change it in oneself, once one finds that part of oneself. Relinguished Responsibility - Look at the responsibilities one has given up or areas one has withdrawn from by being in a relationship. Find corresponding parts that have been lost. Secrets - Examine what the parties keep secret from each other.
Secrets tend to build and make the parties grow further from each other.
If the person defends the need for keeping certain things from each other, that is a bad sign. Find the fixed ideas, find out what the person isn't facing, what she isn't taking responsibility for. There might be past incidents to re-experience, or future incidents. Diagram - Have the person draw a diagram of the relationship. Who takes care of what, who goes where, how is the territory divided up, how are things organized and scheduled, who gives what to whom.