I would recommend splitting all of your family's expenses -- including debt (credit card) payments -- proportionally to your income. If you make 85% of the family's joint income, then you pay 85% of the bills, and she pays the other 15%. ANYTHING that she spends frivilously, or in any way on OM, comes on TOP of her 15%.
Which is probably more than she's paying now??
Are you in a position to be able to pick up more of the load child-care wise, even during the day, with your job? If you do have flexibility there, your atty may be able to hire an occupational evaluator, and "impute" a fair full-time income to your wife should the two of you divorce.
I did go thru a similar sitch with my wife. All she kept belly-aching about was her "bill." SINGULAR. ONE credit card bill, the majority of the balance of which was for tummy-tuck surgery. I told her I would only pay ONE-THIRD of that monthly payment, since about 2/3rds of her outstanding balance was for the elective surgery, which she of course used to make herself more attractive to another, younger man. She went BALLISTIC over this, and kept saying how "unfair" it was, because "you make MORE MONEY than I do!!" And I was like you, paying those $8k of bills! (our monthly expenses are about $10k). She kept screaming at me "You HAVE to pay most of that bill! You make more money!!"
So I finally said "Look, I'll tell you what. I make about 90% of our joint HH income, so why don't I pay 90% of your credit card bill, and in fact 90% of ALL of our bills, and you can pay 10% of ALL OF OUR BILLS . . . okay?"
