I have definitely done sporadic couples work with adult clients and it had gone well. I misread it as working on the marriage to mean making an overall change to couples focused work... My training is in family systems as well, and yes we are trained to work with dyads (couples, parent-child, etc) and the system as a whole. But the role has to be pretty defined from where I was trained. Either you are primarily individual, or primarily family/couples. Switching it up throughout every once in a while isn't seen as an issue, but when that line is blurred - am I x's therapist, family therapist, couples therapist? - it can create problems. Again, this is just the way *I* have been trained to handle it.

Good luck, follow up and let us know how it goes.