Also, I don’t get the thing about the New Republic busting a trade. Seems superfluous and needlessly confusing.
Insert any reason why the Sith cultists would be out of the picture.
Story idea behind my suggestion;
The cultists traded with Reys parents and happened to have one of the experiments (Rey) on board.
Something happened to them, baby Rey was found on their ship and then adopted by Reys parents. (Ny pretending it is their kid that was kidnapped by the Cultists)
Palpi found out about it and sent an Assassin. leading to the parents seaking protection.
But while they managed to save Rey, the Sith found and killed her parents.
I chose the New Republic as the party to shut down the Cultists because they seem like a faction that would be inclined to give out a “kidnapped” toddler.