The sad part of all of this is that your wife is hearing the truth from the people who love her most, but it is likely having the opposite effect from what is hoped for.
She probably feels attacked, which will make her more defensive and less likely to consider going back on her plans. And will cause her to go running to the one person who supports her, the OM, for love and validation.
The same is happening in my situation, so its easy to point it out in someone else's. I and my inlaws are no better at navigating this. It's hard to keep from bombarding the WAW with what should be obvious to them. That's why we do it - we can't believe anyone could not see how crazy it all is.
What is the solution? Stop bombarding. Everyone has stated their piece, everyone knows where everyone stands. More talk is pointless and will just drive her further away.
Now I need to get better at following my own advice...
WAW Using God Me-43 W-40 M-14 S-11 S-9 D-7 EABomb 5/09 Separated 12/09