If she had her mind altered like Revan her being dropped on Jakku as a child could be a false memory meaning she only got dropped off there once.
That leads to my second point: Her whole backstory as we know it is a lie, which I’d rather not have, as it’s removing backstory for the sake of having a twist, rather than adding to the plot.
All we know about Rey is that she was presumably left on Jakku by her family as a child under the “care” of Unkar Plutt. That’s hardly a backstory; it’s only a notch above a premise for a backstory. Also couldn’t you say that about the “No, I am your father” twist? Furthermore, I am of the opinion that both twists would add to the plot significantly.