Vent here and be calm before the conversation. Good plan.
If it truly is a conversation, then be prepared to explain your wants for the finances and what the needs of the family are. Does she work outside the home?
Me:45, W:45 S:16 D:13 M:22, T:25 Bomb: July 2010 Putting finances in order for "D" Continue to live in same home-separate rooms