Written by Mark Driscoll, and directed by Jesse Bochco, the episode originally aired on the American Broadcasting Company (ABC) in the United States on October 16, 2014.

The episode reveals secrets from Ellis Grey's past as Meredith uncovers old videos and reads her mother's journals, providing new insights into her complicated life.

Alex Karev (Justin Chambers) finds Arizona Robbins (Jessica Capshaw), who asks him to check on one of her patients as she struggles to keep up with the workload assigned by Nicole Herman (Geena Davis).

Callie Torres (Sara Ramirez) focuses on the Veterans' project, while Owen Hunt (Kevin McKidd) and Miranda Bailey (Chandra Wilson) confront Jackson Avery (Jesse Williams) after reading an email from Maggie about her resignation.

Meanwhile, Alex Karev (Justin Chambers) learns that the board’s vote to replace Cristina Yang (Sandra Oh) was not as close as Arizona Robbins (Jessica Capshaw) had led him to believe—it was actually unanimous in favor of Miranda Bailey (Chandra Wilson).

He remained with Adele (Loretta Devine) because of his jealousy and hatred towards Ellis’ first Harper Avery award nomination for the Grey Method.

Rhimes explained, "She lost her ‘person’, her half-sister has shown up, her husband is chafing to go someplace else..." She shared that she had been wanting to explore the "familial grenade" storyline for a long time and felt that the end of Season 10 was the right moment to introduce it.

[1] In another discussion of this storyline, Rhimes mentioned that she and the writers were considering using flashbacks to explore the younger days of Ellis Grey and Richard Webber.

Paulson, who previously played young Ellis in Season 6, was unable to reprise her role due to scheduling conflicts with her work on American Horror Story: Freak Show.

Upon its initial release, the episode was watched by 8.43 million viewers and garnered a 2.4/8 Nielsen rating, ranking #22 in 18-49 key demographic and as the 8th most-watched drama of the night.

Using old clips of Ellis to tell a new story was simply brilliant and totally upped the emotional stakes for Meredith (Ellen Pompeo), Richard Webber (James Pickens Jr.), and Maggie Pierce (Kelly McCreary) moving forward."

"[8] BuddyTV noted the show was "on a roll", praising the narrative structure, "In a superbly crafted episode, 'Only Mama Knows' explores the idea of memory, which is both notoriously unreliable and incredibly subjective."

The review noted that Meredith gains a fuller understanding of the past and how it continues to affect her life, particularly with regard to Ellis and Richard's choices.

[9] TVEquals also praised Pompeo and the overall pacing of the storyline, stating, "Last night’s episode of Grey’s Anatomy was entertaining and served as a useful reminder of how well-adjusted Meredith is, despite the challenges of her childhood."

They noted how the show minimized (Owen Hunt, Jackson Avery) or cut out unnecessary characters (Callie Torres, April Kepner) to focus on the central storyline involving Meredith, Richard and Maggie's complicated relationships.