Grey’s Anatomy: Which Of McDreamy’s Sisters Is Lucas Adams’ Mother?

Adams smiling in Grey's
(Image credit: ABC)

Potential spoilers for Grey's Anatomy Season 19.

There are long-running TV shows, and then there's Grey's Anatomy. ABC's medical drama is currently in the midst of its whopping 19th season on the air, and is bringing things back to basics with a new set of interns and a renewed focus on medicine. One of the new series regulars is Niko Terho's Dr. Lucas Adams, who is actually Derek and Amelia Shepherd's nephew. But which of McDreamy's sisters is Adams' mother?

Patrick Dempsey's Derek Shepherd notably has four sisters in the Grey's Anatomy universe, most of which only appear for an episode or two throughout its long run in ABC. The show has been keeping Adams' parentage a mystery for the time being, so let's break down which McSibling might end up being his mother.

Embeth Davidtz as Nancy in Grey's Season 3

(Image credit: ABC)

Nancy Shepherd (Embeth Davidtz)

Perhaps the most obvious choice for Adams' mother would be Nancy Shepherd, played by Matilda actress Embeth Davidtz. She was the first of Derek's siblings that we met on Grey's Anatomy, dating back to her debut back in Season 3. We watched as she judged Meredith and doted on McSteamy, offering a look into the Shepherd's unique family unite. She would eventually return for an episode of Season 15 episode titled "Good Shepherd" which featured a tense dinner with Amelia and her siblings.

Some Grey's Anatomy fans think that Nancy is Lucas Adams' mother thanks to a recent line which revealed that he was from Connecticut. While not much is known about the Shepard sisters, back in Season 3 it was revealed that Nancy lives in Connecticut. Could this have been our answer, or is the medical drama going to keep the mystery going throughout all of Season 19

Neve Campbell in Grey's Anatomy

(Image credit: ABC)

Liz Shepherd (Neve Campbell)

Another one of McDreamy's sisters showed up back in Season 9 of Grey's Anatomy was Liz Shepherd, played by Scream icon Neve Campbell. After the plane crash, Liz turned up at Grey Sloan Memorial to donate nerves in hopes of helping to fix Derek's hand and save his surgical career. She appeared in a total of two episodes during this time, and was the only one of Derek's sisters to show up at the hospital to help donate nerves.

Neve Campbell's McSibling hasn't been seen since Season 9, but could that change if she ends up being Adams' mother? The actress' schedule might be more open after dropping out of Scream 6, so it doesn't seem totally out of the question. We'll just have to wait to see if the Scream Queen returns to Seattle.

Amy Acker in Grey's Anatomy

(Image credit: ABC)

Kathleen Shepherd (Amy Acker)

The last Shepherd Sister to show up in Grey's Anatomy is Kathleen, played by Angel icon Amy Acker. She was referenced as far back in Season 3, and was also called by Heather Brooks (RIP) in Season 9 to possibly donate nerves for Derek's hand. In the end she wouldn't appear until the Season 15 episode "Good Shepherd" which was about Amelia's relationship with her family. 

Kathleen seemed like the most cruel Shepherd sibling, especially where it concerned Amelia's colorful past and drug history. She even makes a bet about Amelia's break-up with Owen Hunt. It's an episode that shows just how complicated the family unit really is, with Amy Acker giving a strong performance. But like Liz and Nancy, not much is known about Kathleen's husband or location. And as such, she could also very well end up being the mother of Lucas Adams. 

Who do you think is Adams' mother on Grey's Anatomy? For now that remains to be seen, but smart money says that one of the above actresses will appear once the mystery is solved. We'll just have to wait to see how it all shakes out at Season 19 continues on. Luckily for Amelia, Adams has finally revealed that he's a Shepherd, and the other interns no longer think that they're sleeping together.

Grey's Anatomy airs new episodes Thursdays on ABC. In the meantime, check out the TV premiere list to plan your next binge watch.

Corey Chichizola
Movies Editor

Corey was born and raised in New Jersey. Double majored in theater and literature during undergrad. After working in administrative theater for a year in New York, he started as the Weekend Editor at CinemaBlend. He's since been able to work himself up to reviews, phoners, and press junkets-- and is now able to appear on camera with some of his famous actors... just not as he would have predicted as a kid.