Reviving Sims

If you use mods, you can use MC command center by clicking on the sim in the relationship panel and selecting revive.
If not, you can make Ambrosia, but be warned that it takes a while and requires maxed out cooking skill and some other ingredients.
If you have Romantic Garden Stuff, you could use cheats to add the parents to your family and have them use the wishing well although this doesn't always work.

Sorry if this wasn't helpful.

Ok, I made the lot haunted to try and lure them in but still nothing. I'm not even sure where the urns are!

Sadly, I just restarted my rotation save. Lost the Patriarch because I aged him up in CAS. My bad. I had no clue this would happen! Next thing I knew is he was a ghost. I only left that lot for a moment. Oh, well, having a brand new save will surely help after this patch. When I get home from vacation, I hope to be able to get Seasons shortly thereafter. It would be fun to take these Sims through their childhoods again, this time with Seasons. :)