DBing has a lot of different aspects and vectors to come at saving a M. Not least of which because there certainly ARE a million different ways to do something and I am certain that MWD wants to cover as many of the general bases as possible.
At the end of the day, DBing is about SBT (Solutions oriented Brief Therapy) or basically focusing on a small, single, close goal, working on getting there and then moving forward from that point.
What that does is set up for successes, which is always a good thing for PMA. It also sets up for change, which helps to break patterns which can be negative. That ultimately leads to being able to come up with possible, positive solutions to the end goal, which is saving the M.
That said, even if we concede that we have contributed to the break down of our M and resolve to and DO work on those things, it does not have to be a case that our spouses work on issues that we believe they have, that contributed to the breakdown of the M. That work is often only something that will happen AFTER the LBS has done their own work, first.
So specifically to your sitch, even though your W has her issues regarding making and keeping friends, she may only work on those things at a later point, after you have done your work which might motivate your W to re-engage and work on the M.
Hope that makes sense as to how you might approach this.
Are you the type of person that sets your mind to task and are all in? Or put another way, are you prepared to do what ever it might take to save your M, so long as it is in keeping with your morals and ethics?
Or, are you just not really sure that you'd put in the effort if your W won't change? Because that IS a possibility.