Grey's Anatomy Casts Amy Acker as Derek's Sister

at .

Amy Acker is the latest addition to the cast of ABC's Grey's Anatomy. 

According to EW, the actress will play Derek Shepherd's (Patrick Dempsey) fourth sister, Kathleen on an upcoming episode. 

Amy Acker In 2018

If you watch Grey's Anatomy online, you know that Kathleen has been mentioned on several occasions throughout the series, but we've yet to see her in the flesh. 

Given that Derek is dead, the only real link to the action is through Amelia (Caterina Scorsone) who works at Grey Sloan Memorial. 

Related: Grey's Anatomy Season 15 Extended

We do know that Kathleen is a psychiatrist and that she will first appear in an Amelia-centric hour, but there's no telling what actually brings her to Seattle. 

Neve Campell previously played Liz Shepherd, while Embeth Davitz played Nancy Shepherd. 

Amy Acker Attends Fox TCA

It's crazy that, after all these years, Grey's Anatomy is still fleshing out some of the characters who have been on the show for years. 

The show remains a huge success for ABC, currently ranking as the number one scripted show on the network with an average audience of 6.9 million total viewers and a 1.7 rating in the demo. 

When DVR ratings are factored in, the show swells double digits. 

The Amelia-centric hour was confirmed shortly after ABC extended Grey's Anatomy Season 15 to 25 episodes. 

"I knew for a long time that we were making 24," Grey's showrunner Krista Vernoff told press when the extra episodes were ordered.

Amy Acker Attends aTVfest

"We've been making 24 episodes a year for many years now. ABC asked about [doing one more] and I spent a week thinking about whether or not we could accomplish it. I [ultimately] said yes because I like to be a team player."

Related: Grey's Anatomy Set to Introduce Derek Shepherd's Fourth Sister

Acker currently stars as Caitlin Strucker on Fox's The Gifted. The show is not performing well in the ratings and is likely to be canceled. 

Could Acker become a more permanent fixture on Grey's Anatomy? 

That would be fun!

What are your thoughts on this news?

Hit the comments below. 

Grey's Anatomy airs Thursdays on ABC. 

Paul Dailly is the Associate Editor for TV Fanatic. Follow him on Twitter.

Show Comments
Tags: , ,

Grey's Anatomy Quotes

MEREDITH: "You don't get to call me a whore. When I met you, I thought I had found the person that I was going to spend the rest of my life with. I was done! All the boys and all the bars and all the obvious daddy issues, who cares? I was done. You left me. You chose Addison. I'm all glued back together now. I make no apologies for how I chose to repair what you broke. You don't get to call me a whore."
DEREK: "This thing with us is finished. It's over."
MEREDITH: "Finally."
DEREK: "Yeah, it's done."
MEREDITH: "It is done."

Arizona: Oh my God! I mean, I understand why you're into her. She's hot. Wait, she likes you?
Nathan: What? I mean, I'm going to try not to be offended at that.
Arizona: No, no, no. It's just that Derek was, Derek was epic for her. They were the great love story. I mean, that girl's heart beat for Derek Shepherd. It just, it never occurred to me that she would ever be with anyone else. He was perfect. He was everything. That man turned her world. It, I spooked you. Don't be spooked.