Make sure you err on the side of being overly generous (but stopping short of paying for her new iPad, or her cellphone, or ANYTHING that she would use to possibly carry on her affair). You should continue to pay for her health insurance, auto insurance, reasonable monthly needs (personal drug store expenses, small "allowance" that is sufficient but doesn't give her enough to go blow it on legal fees or OM). Something that ANY fair-minded observer would agree is a MORE-than-reasonable plan, but that begins to restrict her irresponsible financial behavior.
No family court judge is going to make you pay for her reckless credit card debt. They ARE probably going to make you continue to pay for her "lifestyle to which she is accustomed," if this should even all come to that, and therein lies the rub. Me, I put everything in writing to my wife to make sure it would come across as fair to any 3rd party who read it, and to make sure I threw in a "of course i will comply with any legal requirement if it ever comes to that, but for now I think this is more than fair."
