From the way you described the situation it sounds to me as if this is a case where, if you were to file on her, you would have to compare how much you might have to lose with how much you might have to gain. If she files on you then you will just have to do the best you can.

One way to figure your risk, is to compare your investment in the "marital property" with hers, as well as your relative incomes. To the extent that hers is greater than yours, in both respects, it could be worth the risk-- but remember that she could still get primary custody and you may have to pay CS. In this event, if there is a house, you may also have to move out but continue paying one-half of the mortgage. If you make a lot less than her she may have to pay you some spousal support or the entire mortgage herself.

If the situation were the same, but you got primary custody, she may have to move out of the house and even pay you some spousal support in addition to CS and one-half of the mortgage. With your having more income and primary custody, again, she would likely be relieved of spousal support or mortgage payments but should still have to pay CS.

All of my comments are based upon the assumption that the law is gender neutral which, of course, in divorce is not always the case. The adultery is not supposed to be considered in property or CP decisions, so I wouldn't necessarily spend the money to depose anyone on this point. Her attorney would object, anyway, and the objection would be sustained. Only testimony of medical experts, or official records, would be considered as far as her mental condition is concerned. I wouldn't file on her, personally, unless I just couldn't stand it any more.