OP you sound just like my mother - overly eager to help because you’re a lovely person who cares about your child!
I understand that!
However, it could (and would, should they divorce) be argued that your DIL never worked or intended to work. It sounds like she is being very upfront about what she wants from life and for over 11 years that has been fine! To now says ‘well things have changed’ isn’t really your DIL’s issue is it?
Things have changed because your son has taken a huge pay cut (not DIL’s fault) and can’t pay the bills he committed to (I’m guessing DIL wasn’t taken into account on mortgage if not earning).
So other than a sense of moral responsibility I don’t see that your DIL is to blame or should go out and work!
If your son left her she would no doubt remain in the house with the children with a mortgage/bills that still needed paying and you would probably have your son living back with you! So not sure that’s an ideal situation either!
You say they’ve been living very frugally so it doesn’t sound like DIL is money grabbing or a total nightmare she’s just lazy and set in her ways- DS knew this and has (until now) facilitated it!
Reading what you’ve said I would say that DS needs to stop ‘chasing a dream’ when he knows that his wife (rightly or wrongly) and two children depend on him to pay the bills!
🤔 it doesn’t much matter if he’s overly stressed, he’s signed up to this life/debts and needs to meet them! I think you know this deep down (which is why you’re subsidising them) but obviously want your son to be happy!
DP has a high salary (well insured too) and I work an average full time job! A condition of me having children (he really wants them) is that I can be at home until they go to school. In fairness I will then go back to my career part time and eventually full time- but it’ll still be 5-7 years of me being at home!
If DP turned around during that time and decided to cut his salary in half by becoming self employed I’d be LIVID!! And certainly wouldn’t be going back to work as he would, in my opinion, have mislead me into having children and reneged on our agreement!
I’m a very supportive and loving partner but I can’t stand when one person just changes things without consultation! It would be the same as me saying ‘I’ll go back to work post baby’ then changing my mind and demanding to stay home - that wouldn’t be fair either!
Your DS has pulled the rug out from under their established lives xx