Dom, you've helped me so much in this past month, I don't know if i could help the "pro" with this. Could you just tell her, "the kids and I are going to xxx for vacation. We will go 12/15/-12/18. Do you want me to get your ticket as well?" Or, have the trip all planned and make sure there is a plan for day 4 as well. If she wants to skip it, she could go home a day early. I bet she wouldn't.
And, going on a vacation with you isn't "arms length" at all.
Me 36 Husband 35 D5 S2 separated: 10/29/07-present Served divorce papers 1/22/09 "When the world gives out beneath your feet, it is time to learn how to fly."