Your character can know and recognize Death if:
→ They've died, either in canon, or in Siren’s Port.
→ Someone particularly close to them has died.
→ They've killed, or otherwise been responsible for someone's death.
→ They have a particular fixation with death.
When and where were they born? (This is fairly simple to answer.)
Has your character died in their canon? (If you could say if they died in their own world, or if being pulled here revived them, that would be very helpful.)
Has your character died while in Siren’s Port? (Again very simple, but important to know if Death can know about this death.)
Has anyone particularly close to them died, whether in canon or in Siren’s Port? (Again simple, though if they have, any names would be helpful.)
Has your character killed, whether in canon or in Siren’s Port? (Names would be helpful, but are not necessary.)
What can Death 'know' about your character? (This can be anything small, from their name or favorite ice cream flavor, to important canon events.)
When can Death bring up the above information? (In private comments only, in front of people, over coffee and breakfast, etc.)
Also, keep in mind that Death is nice, and won't bring up anything publicly that she feels would upset anyone or get them into trouble. That’s not how she rolls. Also, for characters that are from DC Comic canon, they will either know her, or she will know them rather well in comparison to someone who comes from an Anime or Manga canon.