An issue with a genealogy (family) tree.

Hi, I have a problem with the family tree, it's about a sim that does not exist in the game anymore. I've been facing this issue for some time already. I tried to use MC command, the codes I found for him to appear in the parcel, and it managed to delete that sim from the tree... but after some time, the sim returned to that family tree. It's a bit long story, that sim somehow disappeared altogether with his mother, but I managed to get them back from previous saves, but the old version of the kid remained in the tree. 

Do you have any idea how to fix it? MC won't work, because I already tried a couple of times, altogether with this sim to appear on your parcel with some codes, he doesn't exist in the game anymore. So I'd really appreciate some help in fixing the tree if there is some other reliable option you know.

Thank you for your time. 💜
Maggy