The opening seen of The Heat where Melissa McCarthy drags a cheating husband out of the car window is gold for that. I have been divorced for eight years and have a generally good co-parenting relationship with my ex and I put his face in that scene every time. It's glorious.
Anything that will help her escape - her favorite film from when she was a kid; something riotously funny (Girls Trip); just anything that will keep her attention focused on anything but her situation will be a good start. I'd also suggest something like Top Golf, gun shooting lessons, paint ball, -- anything that will takes full concentration.
Seriously though - a movie isn't going to fix the hurt she feels. That's going to take time and likely some therapy.