For her 'Little Toy Guns' music video, Carrie Underwood wanted to keep things a little lighter than the song's serious subject matter.

Underwood says that she started thinking about the video as soon as she started writing the tune with Chris DeStefano and Hillary Lindsey.

"When we wrote the song, immediately you start thinking of video ideas in your head," she tells People. "The whole concept of the song is this little girl hears her parents fighting and it really affects her. There's so many people who can relate to a story like that. Talking about words and how much they can hurt, and you just wish they were more like little playthings, things that didn't actually do any damage."

The video process turned out to be more challenging than expected, though, with Underwood trying to toe a narrow line between paying tribute to the song and being overly serious. So the singer contacted P.R. Brown, who directed her video for 'Two Black Cadillacs,' and he came up with the storyline, which makes the little girl the hero.

"Basically we were like, 'What do we do with this?'" Underwood says. "I didn't want to follow the storyline exactly, and I didn't want it to be too serious, I just really wanted it to be relatable."

And to play the special girl in the video, Underwood instantly thought of Grace Rundhaug, who played Marta in 'The Sound of Music Live!' alongside Underwood.

"Whenever I thought of the types of things I wanted to see in this video, I just saw her face," says Underwood. "She'd be the perfect little girl in the song and in the video."

Watch the 'Little Toy Guns' music video here.

What Did Carrie Underwood Look Like as a Child?

You Think You Know Carrie Underwood?