The title track of Loretta Lynn's 50th studio album, 2021's Still Woman Enough, dates back nearly two decades, to the country icon's autobiography of the same name. Released in 2002, the book inspired one of Lynn's youngest daughters, Patsy Lynn Russell, to jot down a few lines; it took a few more years, however, for the song to fully come together.

Below, Russell tells The Boot the story behind "Still Woman Enough," which features Reba McEntire and Carrie Underwood. As she shares, it was her mother's idea to include two additional generations of country women, which her co-producer, John Carter Cash, speaks to as well.

Patsy Lynn Russell: It dates as far back as the book ... I said then, "Mom, that sounds like another song." I mean, it just sounds like another song. It was probably about -- I don't know. We just talked about it; I think I maybe wrote a couple lines ...

We were going through all of the songs for [the albums Russell and John Carter Cash have co-produced for Lynn, starting with 2016's Full Circle, and] it was on a sheet of paper: "Still Woman Enough." We got to talking about it, and I went home and I finished this chorus, and I brought it back in, and she's like, "You know, I like that, 'cause I've been through some bad times," and I was like, "Well, right there's your first line!"

And it was quick; when we wrote that song and finished it, it was fast.

And it was never intended -- I didn't mean for it to be a duet, but my mom did. When she was tracking the song ... she said, "You know what, I'm gonna have Reba come in here and sing this with me." And it was kind of like, "Okay, okay." Nobody really paid any attention -- we were just trying to get the track down. And then she said, when she went into cut her vocals, "I want Reba to come in and sing it with me," and she had just seen Carrie do "You Ain't Woman Enough" on [an awards show] ...

Mom's way smarter than all of us, because, you know, I'm still playing off of "You Ain't Woman Enough" to "Still Woman Enough" in my mind, and my mom saw a broader picture, that this is really about girlfriends standing together, 'cause we're still woman enough, and the struggles -- we're woman enough to go through those. I think that's part of Loretta Lynn's genius, is knowing those moments, and what those moments are on a broader base.

The final track, I just sat there -- when Reba came in, I couldn't help but be the fan, even though I'd met her 100 times ... I was just ready to cry, because I was like, "How cool is that?"

John Carter Cash: [Reba] was this amazing professional that knew exactly what she was doing every step ... and also attentive and open for ideas and input at the same time ... Carrie's just a wondrous vocalist; she had different ideas and directions and whatnot that we moved with and followed that I wouldn't have necessarily thought of myself.

PICTURES: Loretta Lynn Through the Years