Soooooo something weird is happening...

I have this rather large rotational save (as I do), this time basically made up of two parents and two toddlers each. I just like the toddler stage of the kids best in the game. Anyway, so, I started getting these notifications that some of my characters that were in my gallery but not in the game were npc's in the game and divorcing, remarrying, having kids, etc.....I was like hold on. Wait a second. So I went and found all of them and yes, somehow the game dragged in sims from my gallery!!!! Is this normal? Is this supposed to happen? It is also bad because they added some characters from the gallery and I added from the gallery as playable characters so in one case there are three exact same families, only now split up amongst different households because of npc drama. Kind of confusing. Has anyone else had this experience??