How long has she known?

The note

        The first question is how long has Sutton known that Rebecca is her mom? She could have known this entire season that Rebecca was her mom. So was it her plan all along to have Emma, Thayer and Ethan believing that Annie was her mom? When Sutton came back after the crash, she suddenly treated Emma different. She started accusing her that she stole her life. Even before the crash she did. But was that part of Rebecca and Sutton's plan? Was Rebecca or Alec the one that sent the message that said "Keep being Sutton..or you're next." Rebecca might have sent it trying to make Emma think that Alec sent it. Rebecca's note that she got at the restaurant saying "Don't trust your date" was also on a plane white piece of paper and looked just like that one so did Rebecca send both of them?

Emma and Sutton talking to Annie Hobbs

         Emma and Sutton went to go see Annie at the hospital and after they left Rebecca came and said, "What have you done now?". How did Rebecca know that Annie was in the hospital or told the girls. The only reason Emma and Sutton knew that Annie was in the hospital was because they overheard Alec's conversation on the phone. The only way I think that Rebecca would have known was that Sutton told her.

        Then when Derek was killed Alec told Rebecca that their date was canceled because he had to go find his daughter. But was it Sutton's plan all along to have Emma innocently call Alec asking where Mags was? Once Alec was coming home after "looking for Mags" Rebecca was there. If she knew he was gone and cancelled the date she would not have showed up. I think that she knew that Alec would go see Derek and she decided to go to the house so she could say during the trial that she did go to his house. Or that she would tell them that he came home acting really weird but she just thought it was because of his daughter missing.

Ethan, Thayer and Emma

          There are a few more times that doesn't make sense on how they found out about it. Rebecca has been nice to Emma like when she was telling her that everything will work out and not to worry about Ethan. But Rebecca also is overly nice to Laurel. Maybe because she wants Laurel to like her so she can "replace" her mom.

So is this Rebecca with Emma or Sutton?