How to import grandparents.

@spiritedtreasure    Hello!  There is a game mechanic that adds a kind of placeholder for parents of sims when you start playing them.  Sometimes the Genealogy shows these placeholders as generic male / female thumbnails but not always.  Based on your description, it seems these placeholders have been set for that "grown-up baby" sim.  The only way to add parents to sims at the top of the family tree, once those placeholders are set, is to save the household to your library and then remove them from the save (or create a new save where the households can be combined).  You can then combine the households in CAS and you should be able to also set their relationships at that point.

For your example:

Save 1 - SimA and SimB got married and had baby SimAB.  Then you saved Sim AB and loaded them into a new save.

Save 2 - SimAB had baby SimABC.  Now you want to bring in SimA and SimB from Save 1.

First, save the households that include SimA / SimB and SimAB / SimABC to your library, if you haven't already.  Note: They will retain all traits, as well as aspiration and career progress.  They will not retain relationships outside of the household.  They will not retain money when adding the other household (meaning the combined household money will start as if you've never played them, around $24K I think?).  They will not retain any inventory items.

You could then start a new save OR, if you want to keep playing in Save 2, you'll then have to delete the SimAB / SimABC household.

Either in a new save or with the SimAB / SimABC household deleted from Save 2, go into CAS and load the households from your library.  I suggest starting with the SimA / SimB (grandparents) household; double check they are spouses.  Then load the SimAB / SimABC househld and choose the Merge option.  Double check they have parent / child relationships.  You should then be able to set SimA / SimB as SimAB's parents and, by default, they will be set as grandparents of SimABC.

Please come back and update if this worked for you or not.  Let us know if you have any questions or encounter any problems.

Yes, this is what I did. Thank you for your help. It seems to work if you start by importing the great grandparents first. But the game seems not to recognize that they are the great grandparents. You lose the friendships, but it’s done anyway. Thank you.

@spiritedtreasure   It's not an ideal system but it's what we have.  Hopefully you're able to make it work. 

When you said the game doesn't recognize great-grandparents, do you mean it doesn't assign the actual label or they're not showing in Genealogy?  The relationship labels only go back to Grandparent when looking in the Relationship panel.  However, the great-grandparents should still show in the family tree.

What I mean is that they showed up as great grand parents in the family tree. But when I went to meet them with her, they didn’t show up as anything, just friends. So when I went to visit the grandmother and the mother yesterday. They were both crying and crying and I didn’t understand why until I tried to visit the great grandparents and they’re dead. Nobody lives there anymore. And apparently there is no urn if the NPC doesn’t die in front of you. Or the townie. I got no notification because the game doesn’t realize that they are related.

A bit weird.

@spiritedtreasure   Oooh!  Okay.  Thanks for the extra information.  You're right that the game does not track great-grandparent relationships even though they're in the family tree.  It would be nice if they would add that and I've seen some feedback posts asking for more extended family relationships, so we're not alone in wanting it.  You're also correct that you do not get urns from sims if they die while you're not playing them.  The only way I know of to get an urn after a death is with a mod and some cheats, unfortunately.  It's definitely odd that you did not get a notification about the deaths if your sim was friends with them.  Although, I believe the sims have to be at least "good friends" to get that notification.

No, we weren’t good friends yet. I was working on that. They seem to be in a world of their own to be honest. I’m glad I brought them in but to be honest if I had known that it would’ve been like that I probably wouldn’t have. So I have moved into their house and I have found a couple of magic looking gravestones in de bug that I set out to be their “graves”. This is my ancient spellcaster, so all her ancestors are/were spellcasters. It’s a nice little house made by Lilsimsie.

added: i’m on the PlayStation five, so no mods for me.

@spiritedtreasure   Aww ... okay.  I'm glad you found those debug gravestones for them.  I do wish there was some way to get urns / gravestones for played sims even though you're not playing them.  Maybe something to consider when you have elder sims is to leave a younger family member in the house with them or move a younger friend into the household?  There have been a couple times when one of my sims died while I was playing another household.  I was able to load the household that had the sim die and found the urn on the lot.  I don't know if it's supposed to happen that way or if it was a fluke.  Also, this was a while ago so I don't know if it would work now.  Just a thought.

By the way, I don't think it's a total waste.  At least you have the great-grands in the family tree, right?  Anyway, I'm sorry it didn't work out exactly as you hoped. :-(