The most important thing you can do is simply be there. She may not remember every conversation, everything you did to help…. but she’ll know that you were there. It’s a hard thing to think about, and something none of us actually want to be a part of. It should never be anybody’s turn to be away from their family for so long, not to experience a casualty, not to have to support a friend through any crisis.
But, from personal experience, some of us will be in this position, and more than once. If you find yourself there, be sure to pick your action. Don’t put the ball in her court. Support her and the family in real and tangible ways. You won’t be able to comfort them, but YOU can find comfort in knowing that you supported them in a very real way.