So very sad. Happened to me, not once but twice. Third times the charm.
Besides running, which I agree wholeheartedly with, the only additional advice would be to have a man to man talk with her father. Get some advice from him.
Hell, he may actually endorse the run now option and you might not feel so bad about it.
With my experience I gave the run now advice to my brother prior to his marriage. He didn't talk to me for six months. Now, he just shakes his head that he didn't listen.
Best of luck to you. Hope the second marriage goes better.