Twin Theory Still Might Happen on PLL

What happened to that theory that there would be twins on PLL?  Last year, Tammin Sursok (Jenna Marshall on PLL) confirmed in an interview that someone would have a twin sister on PLL.

We may have found out who “A” is, but that doesn’t mean the twin theory didn’t pan out.  It still might come into play when PLL returns.

When asked about the twin theory by a fan on Twitter, PLL showrunner Marlene King tweeted “The story isn’t over.”

The story isn't over. @aguerin32 #Twins

— I. Marlene King (@imarleneking) August 25, 2015

 Marlene later tweeted "there is a twin. You will find out soon."

@jeffsewell_ there is a twin. You will find out soon.

— I. Marlene King (@imarleneking) September 7, 2015

Alison and Jason already discovered that Charlotte/CeCe was their secret sister, although she wasn’t a twin.

So do you think we will see a twin when PLL returns for the second half of season 6?  Who do you think has a twin and how do you think that plays into the story?