I would validate for her that it's good for her recognize and anticipate the anniversary feelings. It hasn't been that long since my dad died, and I get it.
The thing she seems to respond to the best is me saying of version of "You can be sad. You're allowed."
Interestingly, she also seemed to respond to a silly Safe-Space-related acronym I gave to the house last summer. It's like giving the house a title allowed her to realize what I've been trying to help her understand for years... .that's there's no judgment here. Guilt-free grief.
Thanks Gagrl.