One day she hopes to become perhaps Swanhilda in “Coppelia.”

But today she is charged with battling mice.

Langley resident Grace Rookstool, 10, entered the ranks of the infantry when she was cast in the Pacific Northwest Ballet’s production of “The Nutcracker.” Grace is presently hard at work preparing herself for a fierce battle against the Mouse King and his micey minions.

After spending two years at the premiere Seattle ballet school, Grace decided to audition for the famous PNB holiday extravaganza this year and was cast as one of the high-stepping, red-jacketed soldiers.

But to become a ballet dancer is no easy feat, and there are always hours, days, years of practice involved.

The fourth-grade homeschooler has been dancing since age 3, along with some of her nine siblings. She takes about a two-hour ballet class three days per week, in addition to the two hours per week of rehearsal required for “Nutcracker.”

The Pacific Northwest Ballet is famous for its production of the Christmas ballet which takes its story from E.T.A. Hoffman’s “The Nutcracker and the Mouse King.” PNB uses sets and costumes designed by Maurice Sendak, the author and artist best known for his iconic children’s story, “Where the Wild Things Are.”

Being on such an internationally proclaimed stage must be a bit overwhelming, but Grace seems to take it all in stride. After all, she has been dancing for seven years and has even spent several summers taking classes at the ballet school.

She said the hardest part of being in the show so far was losing her teacher’s safety net and all the other bodies onstage with which she must contend.

“The hardest part was when the Ballet Master (Otto) stopped counting out loud for us, and we had to do it ourselves,” Grace said.

“Also, there are a lot of dancers on the stage at the same time, and it can be confusing with so many people doing different things.”

But there are also “Hollywood” moments for the young dancer, such as rubbing elbows with the PNB stars.

“I love getting to see the professional dancers up close,” she said. “My favorite PNB dancers are Carla Korbes and Lindsi Dec.”

But one doesn’t have to be a principal dancer or a soloist to have fans. Grace’s grandparents are coming all the way from Michigan to see her perform, and so is one of her faraway cousins.

“Some of my friends will get to see me, too,” Grace said.

Hopefully her friends and family will get to see her do plenty of arabesques, because Grace said that is definitely her best skill. And although learning new steps is always a challenge for the ambitious Whidbey Island fourth-grader, Grace said she would like to remain a ballerina, even when she is older, if she stays injury free.

“I am getting better at learning things faster because there’s always new steps to learn,” Grace said. “I’ve practiced very hard, and it makes me happy to show everyone my dancing. I love to be on the stage.”

She also enjoys the new friends she’s made through ballet, and is excited by the prospect of sharing the stage with one of her three balletic Whidbey cohorts.

Grace and her ballet buddy, Caelen Coe, also of Whidbey Island, just received the news that they were cast in the PNB production of “Cinderella,” which opens in January.

Ultimately though, Grace said ballet is good for her and good for the world because, when you see a show like “The Nutcracker,” it’s hard not to be happy.

“It makes me have a good mood, because it’s hard to be mad or not in a good mood when you are dancing,” the ballerina said.

Grace will be performing in the “The Nutcracker” from Nov. 26 through

Dec. 27.