Played by Valerie Curry, and she was a damned joy to watch. She took a thankless role that likely was going to be written out early and stayed WELL past her time because she was so damned good and no one wanted to get rid of her. Until now. Where they had stupid CLaire kill her off in the next-to-last episode... well, maybe kill her, since people never stay dead in this show. Claire was likable in Season 1, mostly, albeit stupid; here she shows up halfway through Season 2 after being dead seemingly, coming back to fuck up Ryan's life since he had finally moved on, and then she does lots of stupid shit after being advised not to by just about everyone, and manages to get into a knife fight with Emma and ends up killing her. Claire, who is smaller, less tough, has no training, no experience with killing people, and manages to make some nice clean shots to kill others in a running fight + stab Emma to death. And then, at season's end, after Joe is arrested, she dumps Ryan beacuse "they both have to move on." YEah, she comes back, contributes nothing to the plot except getting a number of people killed because she won't stay put, and then tears out Ryan's heart again by leaving... lol.
Anyway, back to Emma. Shortly before he death, she gives one of the most profound soliloquies on the show -- about death. And we realize she's actually looking forward to being dead... it offers some peace and relief. The idea of silence is actually refreshing to her. It's one of the most honest things I've seen on this show, which I suppose doomed her immediately, but... anyway... at least she manages to go out (1) believing Joe actually loved her over Claire and wanted to be with her, and (2) having come to terms with death and it's less a fright than a peaceful embrace.
She really was one of the highlights of the show.