Don't give her the heads up that you are going to talk. Then she won't be able to plan anything to say. Just wait for a moment when you together next and bring it up then.
M-42 W-40 S-12 D-10 Together-13 years Married-10 years Separated-6/2016 ILYBINILWY-7/2016 EA-4/2016 (best guess) PA-7/2016 (best guess)