You asked the counselor question...all I can tell you is that the counselor I had did NOTHING to keep my marriage and did EVERYTHING to just go with what I was feeling at the time. Psychologists, in my experience, just sit there and listen and let you lead the discussion and go with what you say. Like you said, I think what this counselor will do for your wife is give her someone to talk to, other than the OM, that will have a neutral (possibly pro-marriage) view. Then, hopefully, you BOTH use the counselor as you work to repair the marriage. She, ultimately, has the choice to make. Her free will. Keeping her away from OM completely is what it will take to go through the WD and have her start to see things clearly enough to work on the marriage.