Hi Jack....sorry to hear of your partners dad passing.
IMO there is little you can physically do to help. Emotionally you can:
1. Unconditionally Love her.
2. Accept where she is and how she is feeling without judgment.
3. Support her however she needs it.
4. Have an open heart and choose to listen.
Other then this, I personally don't see a whole lot that you can do.
Again, sorry to hear of this, hope both of you find peace with this soon.
Love!