PLL Spoilers: “A”’s Motivation and a Twin

PLL showrunner Marlene King hinted at a twin on Pretty Little Liars.  She also talked about “A”’s desire to see all the Liars behind bars.

Previously, Marlene said that only one PLL fan knows who “A” is.  Have more fans correctly guessed “A”’s identity by now?  “Yes, but not for the right reasons and not for the correct motivation”, Marlene said.  So now some more fans do know who “A” is, but for all the wrong reasons.

“A” must really have a grudge against all the Liars, since “season five really is about 'A' wanting to punish all the pretty little liars.  Alison is behind bars, rotting away in that orange jumpsuit, but 'A' is not happy just to have one little liar there – 'A' wants them all there”.

Ever since Tammin Sursok (Jenna on PLL) dropped hints about a twin sister on PLL, we have been wondering who has a twin sister.  Marlene makes it clear that we won’t see Alison’s twin sister Courtney like in the Pretty Little Liars books.  However, "there is a reason why we keep dropping these not-so-subtle clues about a twin, so I would say wait for it.  Wait for it. You're not going to see Courtney, but you may see double of someone."

Do you think “A” will succeed in getting all the Liars behind bars?  And what are your theories on the mysterious twin?