When Shields, 50, was approached about making a guest appearance in the final two episode of Hallmark's When Calls the Heart, the actress immediately knew her answer.
"I didn't even have to read the script to say yes," she tells PEOPLE.
In the show, Shields plays Mountie Jack's (Daniel Lissing) mom, an outspoken, protective frontier woman – which is something the actress says she can easily relate to.
"She's a poker playing, horseback riding, call-it-like-it-is woman," she says. "I identify with her energy – she's one the guys but also a really good mom."
But her favorite part of the role? "Honestly, wearing the clothes," she says.
In the exclusive photos of Shields from the show, she dons a pioneer inspired ensemble, complete with a leather wide-brim hat, an oversized brown jacket and riding boots.
Catch Shields in the season 3 finale of When Calls the Heart Sunday at 9 p.m. ET on the Hallmark Channel.