Lexi Walker, a 14-year-old blonde from Sandy, a city in the US state of Utah, made her first trip to China recently along with her parents.

Like many new visitors to Beijing, they went to see the Great Wall, the Forbidden City and relished Peking duck.

But Walker isn't an ordinary visitor. Her performance at the opening ceremony of the Beijing International Film Festival on April 16 thrilled the audience.

The annual cinematic event concluded at the weekend.

Playing the role of Elsa, the lead character from the 2013 animation hit Frozen, Walker sang the movie's most famous song, Let It Go, along with Chinese pop singer Su Xing.

The song had won the Oscar for best original score.

"I never expected to perform in China or work with a Chinese singer," Walker tells China Daily.

"It's so exciting to sing in front of new audiences."

Two years ago, after she sang the same song along with American singer-actor Alex Boye and the One Voice Children's Choir from Utah, their online video was viewed more than 72 million times, according to Sony Music.

Since then she has appeared at several US venues, such as Carnegie Hall, the Disney Christmas Day Parade and Kennedy Center.

Last November, she released a holiday-themed debut album, Merry Christmas, featuring traditional and new songs.

She is also working on a crossover album with Sony Music, which is likely to be released later in the year.

Walker wasn't formally trained in singing while young but she was surrounded by music, thanks to her grandmother, a longtime music teacher at a local school.

As a child, Walker once had a crowd gathered around her as she sang a Beatles number while sitting near a stuffed toy in a shop, she says.

"I have been singing ever since I can remember. I don't feel nervous before performing. I just feel excited even when I am about to reach a high note that I have never done before," says Walker, who is also a member of the One Voice Children's Choir.

"I have always loved singing. It is one of the best ways to express how I'm feeling."

She decided to become a professional singer after she performed the US national anthem at a soccer game in Utah in 2013, and it fetched her much public attention.

"It wasn't until later that my mother told me that many people watched my performance. I'm really glad that people liked it," says Walker.

Things have changed a lot for her with popularity. Now, she has coaches and family members working alongside her on her schedules.

Her parents appear humble about their daughter's success. Her mother, Lisa Walker, tours with the daughter as her manager. Lexi is the fifth of the Walkers' six children.

"We just keep things open for her, taking her to nice places and to meet nice people. We let her decide what she wants to do," Lisa Walker says.

"I'm her manager but I'm a mother first."