Yes she did but why return after like 500 episodes where she got barely a mention at all?
The fact that she had an effect on his life doesn't account for why she returned they just decided to reshow her and growlie
Well Jessiebelle didn't show a lot of time and then back. It all depends on the plot, and sometimes people meet in other regions. They don't need to remind her, because Dawn doesn't know her anyway, so Ash and Brock can not tell her about Duplica (especially as it was a long time ago and there is no real point in mentioning her).