Where does Sydney come in to everything?
Sydney is connected to both Jenna and Mona. She clearly knows a lot about what's gone on, but how does she fit into all of this? Surely she couldn't have know Alison from before she disappeared because Ali would have said something to the girls, right?
Theory 1 (What a lot of people think): There have been a lot of theories that Sydney is related to Jenna, which could explain a lot about why she's come into the show. It's a little late to come into a show without any real explanation, which we haven't had so far accept that she knows Jenna & Mona. Other than that her character is pretty pointless so far, so something big MUST be happening with her. The girls have done a lot of bad things to Jenna (especially Alison) so she could have come to help Jenna seek revenge on Ali with the help of Mona & Mona's Army. But Marlene has had her planned since about Season Two so she fits into this more than we realise at the moment.
Theory 2 (My Theory): What if Sydney is related to Bethany? We know that Bethany is the same age as the girls and that Sasha Pieterse has confirmed that Someone has a twin but it isn't Ali. So it could be Sydney and Bethany that are twins, which would also explain why she's recently just come into the show. She only came into the show when Alison came back, maybe because she knew that Bethany was in Ali's grave all along? (I'm not entirely sure how she would but this is Pretty Little Liars so anything can happen) and now she's come to Rosewood to find out more about Alison and the girls and what really happened to her sister. Which would explain the text at the end of the last nights Show (5x07) "New York, New York it's a hell of a town. Ali's keeping secrets, maybe because of Hanna's big mouth" because Hanna let it slip that they were in New York, NOT Philadelphia. So Maybe Sydney has joined the A-Team to find out more about what happened to her sister. Bethany is quit clearly connected to Mrs D, so Sydney might think she's some how connected with Ali, and possibly that Ali was the one to kill her, especially since she was buried in Ali's back yard (where Ali was buried alive but later got pulled out) she might think that Ali killed Bethany to make people think it was her & want's to find out the truth. We know how people on this show can go to extreme lengths to find out the truth. (e.g. Ezra)
Anyway, these are just a couple of theories i believe could be true, obviously both have flaws because we don't have enough answers to say for definite.
So tell us what you think about both the theories, or tell us what your theories are!
Let me know your theories! Kisses - L.