Loads of great ideas.
Meaningful holidays, anniversaries, bdays, etc. Will be hard for her.
But, as her friend, you can help!
Get to know her & plan a meaningful holiday (anniversary, etc.) Celebration that honors him & their marriage.
Set an extra place at the table for him in his honor.
The biggest issue survivors had was literally thinking they were going nuts because they sould still feel, see, smell or otherwise sense their departed loved one with them!
I'd ask, "where would you be if you'd departed? With your spouse, kids, etc? Or off in some other place?" Bovine stares, then huge smiles.
Sometimes, people just need permission to think independently.
One very religious woman gold me, "Well, the Bible doesn't talk about this."
I asked her if she'd ever been to the Field Museum (Chicago). She said he had.
I asked if shd saw the huge dinosaur skeletons. (You cannot miss them lol)
I got her to agree that they are real & had once lived on earth, then told her, "Well, the Bible doesn't talk about ghem either, does it?"
I swear she looked like the weight of the world had been lifted off her shoulders.
Her mil had lived with her during hospice care & after she died, this woman would hear the unique scrape, clomp sound of her walker, increasing in speed & intensity until the woman acknowledged her mil's continued presence. Then it would stop.
Hospice folks are full of such stories. Think outside the box & give her permission to just be her.
Another biggie is survivor's guilt. Thinking & feeling they could have done more, or should have known something they had no way to know.
Emphasize that she did the best she could for him with her resources & abilities.
Perhaps convince her to connect with a hospice for individual or group therapy. They are specially trained to help others deal with loss.
Some have widow support groups & groups are very powerful for healing. She might also meet new friends there to broaden her social support structure.
She is quite elderly & fearful of how she will accomplish the tasks of living while alone. Empower her with friendship & resources. 😉