Well [They] did just convince large portions of the population into believing the air between the door and their table was toxic
I would suggest confronting head on with a calm mind. Ask the questions and collect the answers. This will tell you the character of the person. Be prepared for lies and reverse accusations. Typical emotional response stuff. If it proves she lied than there is nothing worth fighting for. She already would have left the marriage
You lose depending on the side. If you spend it all before a divorce than you just split the debt, but you will have a boat and a bunch of other shit