Based on my short term understanding, everyone who deals with an A ending the relationship and ends up here tends to do a lot of self-reflection and learns quite a bit about themselves.
Whatever negative experience we encounter, and the ending of our hopes/dreams and shattered expectations - we can rise from the ashes as a better person, and maybe help others we see facing the same demons.
The most gut-wrenching part of dealing with a WAS is the absolute selfishness and lack of concern on their part of the LBS feelings and predicament. Doubly so when we are engaged with people who suffer from some sort of disorder which makes them incapable of empathy even in normal situations. Triply so when you have children of the M who you care for, and who cannot handle the emotional roller coaster.
We didn't ask for this situation, but the way we respond to it says a lot about who we are. One quote I reference as interesting:
“When two people decide to get a divorce, it isn't a sign that they "don't understand" one another, but a sign that they have, at last, begun to.”
Unfortunately we end up in a "please the WAS at any cost" series of behaviors, and the GAL/Distancing only seems to push away some, yet attract others.
I guess what I'm trying to say... I know it rips your guts out to have come to the realization, and you'll probably start having feelings that "maybe" you can turn things around and begin doubting your course of action. But it will be important for you to focus on your objective, and ultimately focus on yourself - not in a selfish way, but in a healthy way. You can't afford to neglect your own needs as an expense towards pleasing someone who doesn't empathize with your sacrifice.
Your M, your business. But eventually many of us LBS come to the realization of what is and isn't healthy and become the WAS. Don't be shocked if you see your W start pursuing after being "rejected" because that is in the nature of unhealthy relationship dynamics and boundaries. But possibly be thankful if she has an A to occupy her thoughts, because it may make her less caring about the reality of the financial situation.
Remember first and foremost - Mrs Puppy is an adult. It is unhealthy for you to try and educate her on the reality, finances, etc. as much as you want to. She has to make her own mistakes, she has to slip and fall, and she has to learn a bit more about herself at this point. You can possibly shoot yourself in the foot if you try to "care" too much, as difficult as it is we have to lovingly detach from these types of dynamics so that the person can grow themselves.
Hope I didn't ramble too much... but this is my thought process and we seem to think alike in a lot of instances I've seen.
"You can't reason someone out of a position they didn't reason themselves into."