I did a Ctrl+F for “Addison” or “Addy” in the journal transcript. Here are all of the times her name appears.
The title page of the journal says “This Journal belongs to Addison Barrow, actress.”
When Mark gives her the cell phone, he says “‘Open it, Addison.'” On the same page, he says “‘They do know you, Addy. They know you inside.'”
Mark calls her to give her the Sadie’s message at Starbucks: “‘Absolutely totally fine, Addy'” and “‘Addy,’ he said, ‘I am so sorry to have to be the one to tell you this, but Sadie just didn’t know what to say…'” The next couple pages are dialogue between Addison and Mark, and Mark uses her name frequently.
Sadie’s note: “‘ADDISON PLEASE JUST DO WHAT HE SAYS'”
The first time the journal body refers to its subject by name is when Addison is already within the OOA: “Gatekeeper 5 also told me that, if I was going to
stay with the OOA I wouldn’t need to use the name Addison anymore.”
When Mark tries to get her our: “My father says, ‘You don’t konw.’ ‘YOU don’t know, Addy.’ Like I’m a child.” Some of the following dialogue also uses her name.
Those were all the references I found, but that still doesn’t tell us where Sabrina ends and Addison begins. If I were the OOA/OSDM trying to brainwash one person into thinking they were another via a diary, you bet I would include as much of their former life as possible to blur those lines. Memory manipulation is easy, and has been researched extensively (the author of this article is a professor from the university I graduated from). So once again, even after looking at the clues, we know nothing.
Liv 8 years ago.
Thanks 
