That's tough Zee. I want to say the same thing sometimes. I asked my W today if she planned on paying back the money she took from the kids education funds. She looked at me with defiance, and said yes, but it was kind of unfair that she had to pay for her own expenses since January (all her expenses were covered, that money was used and is used to fund her A activities)
I think it's the right call to not say anything right now. Give her your letter, go on vacation, and have a smashing time