I managed to retain my sim's inventory, points, skills, etc., but I did it through merging.
I went into a save file, clicked Edit Town, picked a family from the Family Bin, selected "place copy" for the sim that I wanted to move my skilled one in with, moved them onto a lot, and merged the two families (moved my skilled teen into the other sim's home and left the adult in the other house).
I moved the teen, her new guardian, and their home into the Lots & Houses bin, and returned to my current game. Saved, returned to the Main Menu, and selected New Game. Went back to the Lots & Houses bin to find my family's house, set them up on a property, and entered their lot. Teen retained all of her skills and points. Saved the file under a new name and quit. Convoluted, yes, but she still has all of her points and inventory stuff

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