Why did you allow her to invite herself in the first place? When she did you should have told her no. Just like she told you no about attending HER b-day party or being included in any of her family events/dinners/parties. Sorry, it doesn't work both ways. She says the *only* interaction she wants is about the kids then that is what she will get. She can't change the rules when it suits her and if you let her know it will NEVER END.
No matter how good his intentions are your BIL should NOT be talking to your W about anything that is remotely involved or related to the marriage you and your W used to have or the current situation you are in.
If your W wants to network with other finance professionals tell her to go find a business group in Dallas and network her ass off.
I would e-mail her and say this:
W, I would prefer that you not attend the dinner when my BIL is in town. Things seem to have gotten a bit muddled as an invitation was never formally extended to you. As per your wishes to not discuss anything outside of the children such a dinner certainly would cross a boundary I am not ready to change at this time. I will let BIL know you said hello and best wishes! BTW, I still haven't received the updated custody proposal for the holiday season. I would like it by x (insert date here) as the holidays are rapidly approaching and I know both our schedules are filling up! Take Care! Kevin.
