Having just made it thru my first year without my dh, I can clearly tell you who my friends are... or at least who the brave ones are
I really appreciate the friends who still treated me like their friend, would not only listen to me rave about Mitch, but were more than happy to distract me with discussions of REAL LIFE stuff, not just death and cancer. And they picked up the living room or did the dishes while this was going on... Sometimes they would (and still do!) arrange between them to take my children so I could be home alone or out with friends, whatever I need. One really brave friend sent me an anniversary card (we share the date) -- I was so thankful, not only that someone remembered, but that someone acknowledged it EXISTED, and was friend enough to know that I would need just that reminder on just that day; that our relationship was real and just because he's gone doesn't mean my love for him and for us just vanishes.
Let her talk, and talk and talk.
Ask questions about her memories, she doesn't need them just wandering around in her head with no place to go.
Buy her a journal, buy her lots of journals til you find one that works for her.
Oh, and when you call her six months from now, and her life has been going along fine and suddenly she is just blue... never, never ask "what do you have to be sad about?" you will always, always feel terrible when she says "Dead Husband" (an especially insensitive question near any holidays or the anniversary of his death!)