Your W gave you some good info in this talk. She does not feel like she has a solid support system and it sounds as if she is torn between being a SAHM and a working mom. For a woman that is a hard place to be in. What do you think you can do to support her regarding this issue while not trying to "fix" it?
As far as the money talk why did you bypass the whole budget talk? It seems you went right for the jugular and used the mediator as a threat.
You need to work on validation, patience and listening. You said "I have been telling her to go back to work for a year". That sounds controlling, not supportive.
She needs to figure out the SAHM/working mom issue on her own but it does seem like she is really struggling and fears what others will think. How can you be supportive to that issue without being controlling or a "fixer"? My suggestion would be to listen more than you talk, validate her thoughts about the issue but don't offer advice or try to guide her one way or the other.
She is telling you she doesn't feel supported.
I do think though you really should think about how you handled the money issue. Yes, 1000.00 is a ton of money but she knows that and pointing it out to her put her on the defensive. By using the approach of "lets work out a budget/financial plan for the next few months" it would have given her a good glimpse of you looking for solutions instead of just being upset about it.