I'll keep her, and the others mentioned in this thread, in my prayers.
In the meantime, let me give you something concrete: a wonderful community of Breast Cancer survivors here on the Disboards.
http://www.disboards.com/showthread.php?t=2833381&highlight=gagwta
When I faced my mastectomy, reconstruction and radiation, I got lots of prayers and good wishes, flowers and even dinner for my family for a week.
But the women (and a few men) on that thread have walked in Jennifer's shoes, and yours too. They'll have the concrete advice on what to ask, where to look, and what to look out for. They know the nuts and bolts that only a survivor can know.
Whether or not Jennifer knows or cares about Disney, please point her to that thread.
Again, prayers for her and for your family as you get through this together.
(For what it's worth, my mastectomy was 5 1/2 years ago, and I'm now healthy as a horse!)