There's not much you *can* do - other than to remember all the good she put into the world, and honor her memory.
(plus welcome her back, whatever form she may take!)
I figured though that an "Open Topic" tribute thread would be a good thing, so that if people felt like writing something they could have a place to link.
One of her biggest influences, and sources of strength, was her chosen family. So - things about that would also be appropriate.
I know it's not much, but sending her off to the next adventure, by adding to the stories that she has inspired, seemed to be the way to go.