sims 4 “slain by killer bunny” how to see ghost no urn or tombstone

Hmm... I'll give some suggestions on solving the problem.

As I can see, you tried to use cheats to kill another sim. This has an odd quirk that no matter which sim you click on, the currently selected sim (the one with the PlumBob) will be killed. From accidental saving, I'll take that she was the last sim in the household, correct? In that case, I can't suggest checking the household inventory (as it can be there if it fails to spawn). So, here are some suggestions.

• You can recover the previous save to go back to the times before the accidental death. For this, click Load Game in main menu, select a save, click on Restore Save button, and choose a previous version of the save to recover. A new save file will be made of it, keeping the original there. Do remember that the more you save, the less before-death versions there will be. Here's the picture showing how to do that:
• There are some events (mostly from DLC) that cause ghosts to come. For example:
  • Ghost nights at bars (Get Together)
  • Spooky lot challenge (City Living)
  • Holidays with Spooky Spirit or Remembrance traditions (Seasons)
  • Summoning through a seance table (Paranormal)
  • Haunted lot problems in Residential Rental lots and lots with Maintenance Troubles challenge (For Rent)

I hope you'll see her ghost eventually.