Growing up in St. Paul’s Como Park neighborhood had its perks, most notably falling asleep to the roar of lions from the nearby zoo. But living within a bacon-on-a-stick’s throw from the Great Minnesota Get-Together quickly lost its appeal.

“We weren’t big fans,” said Rachel Keller. “During the State Fair, it became noisy and smelled bad. I grew up with an abundance of things from our garden, so fried food was not enjoyable.”

The 25-year-old actress seems much more at home these days on the small screen, thanks to two breakout roles, the kind that most performers wait a lifetime to tackle. In the 2015 season of “Fargo,” she played Simone Gerhardt, a North Dakota mobster’s daughter whose ambitions earn her a one-way ticket to the woods. In “Legion,” the hotly anticipated FX series debuting Wednesday, she’s a pigtail-sporting patient in a psychiatric ward who catches the eye of David Haller (Dan Stevens of “Downton Abbey”) with her ability to purr come-on lines like Lauren Bacall and shake her hips to a Bollywood musical number. Touch her, though, and she’ll howl louder than any Como Zoo lion.

“Why are the hot ones always crazy?” says a fellow patient, played by “Parks and Recreation” veteran Aubrey Plaza.

But is she really crazy — or a plant sent to convince Haller that he’s really the world’s most powerful mutant? Is she even real?

“Fargo” may have been a coming-out party, but “Legion” is poised to make her a star.

“A lot of great actresses were vying for the role, but she just stole it,” said Noah Hawley, who created both series. “It’s thrilling to discover a new talent, to find those actors who the world hasn’t seen yet.”

On a packed day of promoting the series last month, most reporters were largely unaware that they were in the presence of the next big thing. Most were busy chasing after Stevens, still perplexed why the actor abruptly quit “Downton,” forcing writers to kill off Lady Mary’s beloved Matthew in a car crash.

That will change. Magazine editors will soon trip over yesterday’s It Girls to woo Keller for their covers. Scripts for romantic comedies will pile up. Tom Cruise’s reps will phone about a dinner date.

Keller, who graduated from the St. Paul Conservatory for Performing Artists six years ago, seems all too aware that the spotlight is about to get hotter.

“I enjoy talking about the work, but this part is a little hard for me,” said Keller, referencing her long white skirt and the moments she just spent getting her face touched up before sitting down in an otherwise empty ballroom with a miniature bottle of water and a stylish red-cloth purse. “I’m from Minnesota. I like to be barefoot, running through the woods. There are moments I’ve called my sister and said, ‘What am I doing?’ Maybe I’ll get used to it. Or maybe I won’t. Maybe I’ll just go to Oregon and do theater.”

She wrote a one-woman show during her college years that she’d love to try out in the Twin Cities. Working at the Guthrie would be a dream come true.

“One year for Hanukkah, my dad got us season tickets and I saw ‘Jane Eyre,’ ‘Peer Gynt’ and ‘Midsummer Night’s Dream,’ ” she said. “I’d get all dressed up, we’d valet-park and I’d cry after every show. That was just a beautiful year.”

Whatever path she takes, family members and former teachers agree: She’ll kill it.

“She was not only super-talented, but super-mature and professional,” said Genevieve Bennett, chair of the conservatory’s theater department. “I often felt like I was working with a colleague when she was in the room.”

The seed was planted early. By age 3, she was sitting in on her father’s acting classes at Stagecoach Theatre Arts in St. Paul.

Flint Keller knew right away that his daughter had talent, but he didn’t realize how much until she came home from school one day and read a Shakespeare monologue to him on the back porch.

“It’s hard for anyone to make Shakespeare tangible and real, but to do so at the age of 14 or 15?” said Keller, who now teaches at an elementary school in Florida. “My jaw just dropped.”

Bennett recalls a similar moment when she and fellow instructor Brian Goranson watched their student rehearse a scene from “Proof.”

“We both looked at each other and Brian said, ‘She is going to work.’ ”

Her biggest challenge as a teenager may have been the part of Maggie in Thornton Wilder’s “The Skin of Our Teeth.”

“It’s a much older character and I didn’t think she would have the intuitions and understanding of a character 25 years older than her,” said Goranson, who is now the conservatory’s artistic director. “But when it came time, she delivered the material as if it was a piece of music.”

Keller’s talent was in such demand that NYU and Pittsburgh’s Carnegie Mellon University both offered her full scholarships. Keller chose Pennsylvania. Although she auditioned at the University of Minnesota, she’s glad she took the opportunity to strike out on her own.

“I had a really lovely childhood, but I wasn’t the easiest kid to live with,” Keller said. “As much as my family loved me and listened to me, I needed a little more space.”

Keller clearly channeled those desires to be heard into her two signature performances. In “Fargo,” Simone insists on being taken seriously, even if it means betraying her own family. Syd Barrett in “Legion” may initially come across as eye candy (although her mismatched track suits won’t ignite any fashion trends), but in the first three episodes she proves to be as formidable as any of the series’ other mutants, bravely stepping into Haller’s drug-induced nightmares and, when necessary, throwing a few punches. The question of whether she’s using her powers for good or evil is one of the show’s greatest draws.

“My character feels like a lot of young women who, no matter how supportive an environment they grow up in, feel like there isn’t a lot of space for them to totally express who they are in a way that maybe boys are allowed to,” she said. “Boys are allowed to be a little loud, a little violent, a little explosive, a little expressive and, I think, girls are told to be quieter and a little bit more collected.”

Keller heaped praise on Hawley for giving her room to express herself.

“He’s said to me several times, ‘I’m going to take you as you are. Don’t make any big changes to yourself physically or psychologically.’ He’s been the greatest mentor to come into my life. I thank my stars every day.”

Hawley’s support didn’t mean the role was automatically hers. Keller went through the traditional audition process. But her “Fargo” experience helped.

“She grew a lot on that show,” said Hawley, who has earned five Emmy nominations and one win for the Coen brothers-inspired series. “There was a lot of nerves, a cast with a lot of heavy hitters and not a lot of time. Everyone has to be at their best in the first couple takes, and she had to realize she couldn’t wait around for inspiration.”

History shows that Keller is willing to put in the hours. As proud as her dad is of her small-screen success, he’s equally boastful about the fact that within two weeks of starting school in Pittsburgh, she had secured jobs as a nanny, a hostess and a worker on a juice truck.

His daughter still gets around Los Angeles in a Ford Focus and lives with her grandmother.

“She won’t be throwing lavish parties or driving Porsches anytime soon,” he said. “It’s the work ethic that will be a lasting trait. Being a one-hit wonder is not what she’s going to be.”