The Voice airs Monday and Tuesdays at 8/7c on NBC

Credit: Paul Drinkwater/NBC

Brennley Brown might be one of the youngest contestants on The Voice season 12 , but she has consistently been a standout performer by making old classics feel new.

On Monday’s episode, the 15-year-old California native performed the Linda Ronstadt hit “Long, Long Time” and was met with standing ovations from her coach, Gwen Stefani, and this week’s key adviser Shania Twain.

“I couldn’t believe it,” Brown told PEOPLE of the praise she received. “I’ve grown up with [Shania’s] music from a very young age, I absolutely love her. Feedback from her and critiques, I will take with me the rest of my life.”

She added: “Literally I never in my wildest dreams thought I’d be able to do this and have this experience — especially at my age.”

Of the other country music Brown’s father introduced to her growing up, she lists Willie Nelson, Waylon Jennings, Merle Haggard, Dolly Parton and, of course, Ronstadt.

“I love Linda’s music and it just has that beautiful, classic [sound],” she said. “I hope I made her proud tonight.”

Brown originally joined the show as a member of Blake Shelton’s team, but after he let her go, Stefani swept in and Shelton has said he has regretted it ever since.

“At the blind auditions, I felt like Blake was the obvious choice as a country singer because he’s country,” said Brown. “I’ll always be very grateful to him that he had that spark of belief from the very beginning, but working with Gwen is so amazing. She is one of the most genuine people I’ve ever met.”

As to whether Shelton is helping his girlfriend pick out songs for her to perform, Brown said that she thinks Stefani is “doing her homework on country songs.” And when they’re not rehearsing, Brown and Stefani are sharing funny stories — particularly ones involving horses.

“One time she told me this story about riding her horse and that she fell off. So we had this full-on conversation about horses and how they can trip on their own leg,” she explained. “I went to tell her that I fell off my horse once and it was really funny.”

She added of her relationship with her coach: “I think I’ll always be a little starstruck, but the more that I work with Gwen, it’s more like she’s becoming a friend.”

Tuesday night’s episode will reveal which contestants will move on to next week, and the two with the lowest number of votes will compete for the “Instant Save.” These artists will each perform a new song that represents why they should earn the save.

“If I am in that bottom two, I just will give it all I got,” said Brown. “Know that I’m not going down without a fight.”

The Voice airs Monday and Tuesdays at 8 p.m. on NBC.