×

Grey's Anatomy: Amy Acker Cast as Derek's MIA Fourth Sister, Kathleen

Amy Acker Grey's Anatomy

Grey’s Anatomy‘s Shepherd sibling puzzle is at long last complete. Amy Acker has been tapped to play the pivotal role of late Derek Shepherd’s oft-mentioned-but-never-seen fourth sister, Kathleen, TVLine has learned. As we first reported last week, the character will make her long anticipated entrance in the forthcoming Amelia-centric episode.

Little is known about the mysterious Kathleen (aka “Kate”), but it was previously established that she — like her other siblings — is a doctor (her speciality being psychiatry). Of Derek’s other three sisters, only Caterina Scorsone’s Amelia remains on the show. The roles of Liz Shepherd and Nancy Shepherd were previously played by Neve Campbell and Embeth Davitz, respectively.

“I’ve been doing the show for a long time and just hearing what [the episode is] about fills me with nervous excitement,” Scorsone previously enthused to TVLine of the Amelia-focused hour, which will be written by Julie Wong and directed by Bill D’Elia. “It’s not just, ‘Let’s follow Amelia to the neuro lab.’ It’s definitely a little standalone. It’s almost like a little movie on its own.”

Acker — who is thus far committed to doing just one episode of Grey’s — currently stars on Fox’s The Gifted as moms-to-mutants Caitlin Strucker. Just weeks away from its Season 2 finale, Fox’s lowest-rated, least watched drama has yet to be picked up for the 2019-20 TV season. Acker’s extensive TV resume also includes stints in Person of Interest, Dollhouse, Alias and Angel.