Grey's Anatomy: Real-life sisters Kelly, Crystal McCreary on acting together

Warning: This article contains spoilers about Thursday's episode of Grey's Anatomy.

Maggie Pierce has a complicated family history, and on this week's episode of Grey's Anatomy, well, things got even more complicated. It all started when she met Richard's brother, Chris, and his niece, Sabrina. They were in town because Sabrina was diagnosed with a massive heart tumor, and when she started crashing, Maggie stepped in to save the day. Only, she wasn't able to save the day, and Richard lost his niece. But there's something else that makes this story special: Sabrina was played by Grey's star Kelly McCreary's real-life sister, Crystal.

EW spoke with Kelly and Crystal about their experience filming the emotional hour.

ENTERTAINMENT WEEKLY: Was this your first time acting together?

CRYSTAL MCCREARY: Ever!

KELLY MCCREARY: It was our first time acting together ever. We started out acting at different times but started acting professionally around the same time and we were just like trying to get jobs. [Laughs] We never had a chance to actually do anything together. We were trying to audition and keep roofs over our heads.

CRYSTAL: [To Kelly] Do you remember when, I had this one role on some soap opera and you were like, "Oh my God, if you need a sister, this is our chance!" I will never forget that, we were like, "This could be it!" All the plays that we would audition for never had family members, that was the one time it actually came up as a possibility. But this is the first time it actually happened.

Kelly: [To Crystal] But do you remember the time when I did a summer at the Williamstown Theatre Festival and I did a play with Kathryn Hahn, and Crystal came up for a visit and Kathryn was like, "Oh my God, you're both actors? Divide and conquer!" [Laughs]

CRYSTAL: Yes, I remember that!

KELLY: But we never had a chance to until now.

So how did acting together on Grey's come about?

CRYSTAL: Magic.

KELLY: I heard whisperings about a story line last season where Maggie would have a chance to meet some of Richard's family, and people in the writers' room and Linda Lowy, our casting director, and Debbie Allen all knew I had a sister who acted. That was way before there was ever a script or any certainty that something like that would happen, but everybody else already had it in mind as the germ of the story was growing so when it finally did come to fruition, Crystal had to audition.

CRYSTAL: I did, I got that call on a Friday and they were like, "We need this by Sunday" and I was like, "Okay, I guess I'm not sleeping all weekend!" I had to drag a friend to run the scenes with me all Saturday, put me on tape and by Sunday I was like, "Okay great, that just happened." And I sat around and waited like you always do, hoping the answer is "yes," and it was! [Laughs]

If you'd never acted together before, was the experience what you expected?

CRYSTAL: It was better. You spend a lot of time in acting class honing your craft and you think about all the things you have to do to prepare a character, and I hoped to just be able to do that in a way that I've done with so many actors before with my sister, and it was actually better than what I anticipated just because she's on the show, she had so many stories and great tips for things that I just didn't have any context for because I had never been on the show. To be able to learn from her and be able to get quick tips here and there, it made my experience better. And then, of course, the story line was so intimate so the experience was way better than I ever thought because I had a full arc and her character's so rich already, so we really got to do fun, deep work together and how can you picture that? It was way better than I expected.

KELLY: There are so many awesome family teams of talent out there, the Smiths and the Wayans, and you can tell that they're having a ball making stuff together. It's the thing you love most and you get to do it with the people that you love most and it's the best. It's really awesome! You can't imagine that work can be as much fun as that until it's actually happening.

CRYSTAL: I was pretty sentimental when it ended too because it was like, "Oh my God, that just happened and who knows when it will happen again?"

Crystal, did you know your character was going to die?

CRYSTAL: I actually started reading the script and I texted Kelly being like, "This is so good!" But it was before I got to the end and then I literally was crying at the end. But it's so well written that even though it broke my heart, you can feel that, in terms of Maggie Pierce's arc, it's critical. It's a critical part of her character's life journey so it was also a real honor to know that I got to help my sister experience this big uptick in terms of the stakes for her character's life. I got to help with that! So it was really sad but it was also really triumphant.

Kelly, what was it like for you to film the scene where your sister's character dies? Did it affect you differently than other scenes?

KELLY: Everyone at the table read was like, "Oh boy, this is going to be tough," and I didn't know how that would show up. I'm pretty good at playing pretend, so I was like, "She's playing Sabrina!" And the way that it came up for me really did catch me off guard, which was in a rehearsal of the O.R. scene. She wasn't even in the room and I think that's what it was. It was the opposite of what you might think: When she was in the room being Sabrina I was very convinced that she was Sabrina, but when I thought about my sister being on the table, it caught me up.

CRYSTAL: I actually heard about it. One of the cameramen came up to me at one point and he was like, "I just want you to know that Kelly had a moment because she was really picturing you and she started to cry." For myself even, I was in video village as they took the various shots for that scene and I sat there the entire time and every time they did a new shot, I cried watching her, knowing that she was imagining it was me. That's when it occurred to us: Our family's going to have a hard time with this, it's going to be hard for people who actually know us, because here we are acting it out and it's really overwhelming.

Ending things on a lighter note, what was your favorite scene together from the episode?

KELLY: It was the one where we were waiting in the hallway.

CRYSTAL: Mine too! It was so cute.

KELLY: We're discovering each other and getting to know each other and each of them finding delight in one another, it was adorable and so fun to play.

CRYSTAL: And really fresh and honest. I felt like it was so us, so natural. That was a great scene, that was really special.

Grey's Anatomy airs Thursdays at 8 p.m. ET on ABC.

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