Emily is just a year older than each member of the Group and fits the features of every single victim they've targeted: blonde with brown eyes. She wears reserved clothing and has mid length hair.
Emily has a wounded personality. Having suffered a traumatic experience, she's lived 20 years with the memory of what happened to her. She's very protective of herself, keeping her house barred and secure. When talking, she has a reserved and defensive attitude. But when it comes to Jordan Chase, she shows admiration as if she feels a romantic connection to him. Although Jordan doesn't have romantic feelings for her, he does feel a special bond because she was his first victim. Jordan uses Emily's feelings for him to manipulate her.
When Dexter Morgan begins having sessions with Jordan Chase to try and find evidence of his crimes as being apart of The Group, he eventually notices a necklace with a vial of blood attached to it. Dexter schedules another session for the following morning, intent on taking a quick sample to process the blood eventually he gets his chance and places the sample within a blood slide, though as he leaves Jordan realizes that his locker was open (even though slightly) and discovers a spot of blood on his finger after picking up his necklace. He immediately suspects Dexter and targets him for his own purposes.
Dexter takes the sample back to the lab, meeting up with Vince Masuka to where he has to make up a quick lie that the sample is for a homicide victim he mistakenly forgot about. As events go on where his stepdaughter Astor Bennett disappears with her friend Olivia, Dexter assumes that his tampering with the blood sample has caused Jordan to actively seek out his family and he instantly believes Barry Kurt to be one of Jordan's men. However, this turns out to be a completely different case and everything plays on until Dexter finally is able to figure out who the sample belongs to a woman named Emily Birch.
Both Dexter and Lumen investigate Emily's house, meeting up with her only to get nowhere with their investigation. Though when shown a picture of The Group, she clearly shows an expression of dread. Dexter takes note of this and Lumen later appears, carrying a video of her own torture so that she can fully communicate with Emily. The two sit down and talk, with Emily revealing the truth behind The Group and how they knew each other. Apparently, Jordan Chase's real name is Eugene Greer, a heavyset teenager that inspired the rest of his friends to rape and torture Emily. After they were finished, they forced her to snap a picture and this truth was relayed to Lumen, along with the identity of Alex Tilden.
Later on, Emily is seen talking with Jordan and it's revealed that he told her to tell the truth, everything just as he expected. They appear to share a very deep relationship, meaning the two share something very special. She's shown to appear in the next episode, however, in the episode following on from this, Emily attempts to lure Dexter and Lumen to her house, saying she wants them to protect her as somebody told Jordan that she talked to them. Lumen arrives at Emily's house without Dexter (at the time Dexter was kidnapped by Liddy) Emily made it obvious that she wanted both of them there, and we then find out that it was a setup and Jordan Chase was there waiting for them. When Jordan discovers that Dexter is not present, he angrily beats Emily to death with a fireplace poker before ordering Lumen to come with him or face the violent death Emily had just suffered.