Meg Donnelly was blessed with some helpful practical advice from her Supernatural-universe son Jensen Ackles while filming the short-lived prequel series The Winchesters.

"He gave me a note on never to sink into my heels when I'm standing, especially next to Drake [Rodger]," she told Michael Rosenbaum on a recent episode of his Inside of You podcast. "He learned that standing next to Jared [Padalecki] his whole life," she explained. Ackles told Donnelly that "'you have to stand tall so you look taller, because if you sink into your hip, you're like two inches shorter.'"

Ackles is by no means short, but he practically pales in comparison to his Supernatural brother Jared Padalecki, who stands at 6'4" tall. "'Learn from me,'" Donnelly recalls Ackles telling her, "'you gotta stay tall.'"

Matt Miller/The CW/Everett

While Donnelly only had 13 episodes to practice her posture before The Winchesters was canceled, Ackles shared the screen with Padalecki in Supernatural for 15 seasons. By the time that series went off the air in 2020, Ackles, who'd been cast at 27, was 43, and Padalecki, who was 23 at the outset, was 39.

Shortly after Ackles' "really sad goodbye" to Supernatural, he co-founded Chaos Machine Productions with his wife, Danneel, and got to work on their first project, a prequel series to explore the lives of his and Padalecki's characters' parents. Donnelly, who was cast as the younger version of the Winchester boys' mother Mary Campbell, recalled Ackles and Danneel on set "like every day" while the pilot was being shot. "When we were filming, he would come in and out," she explained.

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Ackles returned as the voice of Dean Winchester to narrate The Winchesters, and was joined by Supernatural alums Alexander Calvert, Jim Beaver, Ruth Connell, and Gil McKinney in a range of recurring and guest roles.

The Winchesters was actually The CW's third attempt to capitalize on the runaway success of Supernatural. In 2014 the network aired a backdoor pilot for a series to be titled Supernatural: Bloodlines, but it failed to pick up steam. Wayward Sisters followed the same formula in 2018, and also failed to capture the fan base.

Donnelly addressed the fickle Supernatural fan base, saying "it was nerve-wracking" stepping into the shoes of a character like Mary Campbell, who'd been portrayed across nine seasons of Supernatural by both Samantha Smith and Amy Gumenick.

"The fan base is just so loyal, and they love the project so much, we just wanted to make sure they liked the portrayal so much," she told Rosenbaum. Donnelly reunited this year with Ackles in the animated DC film Justice League: Crisis on Infinite Earths, in which she voiced Supergirl, alongside Ackles' Batman.