Rebecca Sugar, the creator of "Steven Universe," and her brother Steven Sugar, the inspiration for the series. (Courtesy of Cartoon Network/Courtesy of Cartoon Network)

Rebecca Sugar is about to make a little TV history. And right now, she is not entirely enjoying it.

“I’m having a hard time feeling good about all this,” she says, with a half-laugh, “until the first episode is on.”

Sugar sounds so calm and confident, though, that she belies this case of show-biz nerves. Yet the moment must be noted.

By following her artistic passion from Silver Spring to Hollywood, Sugar has become something of a trailblazer. On Monday evening, Cartoon Network will debut its newest program, “Steven Universe,” officially making Sugar, at just 26, the first woman to be a solo show creator in the channel’s 21 years on the air.

She is thrilled to achieve the breakthrough, but with just days until the debut, she’s not focused on being the first female creator — she’s too busy simply being a creator, with plenty to still decide and coordinate.

“It’s definitely a whirlwind,” Sugar, a veteran of Cartoon Network’s popular “Adventure Time,” says of steering her own show to launch. “But I feel more ready than if I hadn’t made so many independent comics and done so many films.” Everything, in other words, feels as if it’s been naturally leading to this opportunity. From that, the animator draws confidence.

Sugar’s creative vision, after all, wasn’t just born at Cartoon Network’s studios in Burbank, Calif. Her dream to do precisely what she’s now doing was launched many years ago, a coast and an ocean away, back home in Montgomery County.

“You can’t wait for someone to give you a show,” says Sugar. She’s long been an ambitious artist who regularly attended Baltimore Comic-Con and Maryland’s Small Press Expo to listen and learn from luminaries while also getting professional feedback on her portfolio. “That can’t be the first time you’re writing and drawing a character.”

Sugar summons inspiration from characters she has created since childhood. “Steven Universe” may appear to be an action-fantasy cartoon about gem-powered superheroes, but beneath the bright tints and battle scenes, the show plays like an ode to Sugar’s artistically supportive upbringing in Sligo Park Hills. The program is even named for her younger brother, Steven — who is a background artist on the show.

“I realized, while working on the show, that it’s not what I thought it was going to be about. It’s about how much I needed emotional support in high school — just with little things, going through tough times, high school teen angst,” says Sugar, who simultaneously attended Montgomery Blair High and the Visual Arts Center at Einstein High.

“My brother would just be hanging out with me, not having to say anything. If I ever felt weird around friends, Steven would always be there. I felt that would never change.”

Sugar stops herself, joking that she should move on to another topic before she gets verklempt.

“Aw, that’s nice of her to say!” Steven Sugar, 23, replies to his sister’s sentiment. “We spent a lot of time together as kids watching cartoons, playing video games and drawing. We’d brainstorm ideas for comics together, run ideas past each other and get critiques — all of which sort of set the groundwork for what [we’re] doing now.”

In the new show, three female superheroes named for their gem-related powers — Amethyst, Garnet and Pearl — are shepherding irrepressible Steven, an ever-smiling boy who hasn’t yet discovered his gem power. Rebecca says that to write each character, she thinks about how she interacts with her brother — from the laid-back Amethyst to the authoritative Garnet. (As for having his name in the title, Steven says: “It’s always been a bit surreal, and a bit flattering, too.”)

“Steven Universe” is set in the fictitious Beach City, but the locale “is rather significantly inspired by the beaches Rebecca and I visited when we were kids,” says Steven — who also attended Einstein’s Visual Arts Center before going to the Rhode Island School of Design. “There are a few not-so-subtle references to Rehoboth Beach in there. The whole town is a sort of amalgam of Rehoboth, Bethany and Dewey.

“I find it pretty cool,” he continues, “that so much of the non-magical side of the show comes from something so grounded in reality.”

The Sugar parents were both animation fans and always creatively supportive. Rebecca began attending North Bethesda’s Small Press Expo at age 15 and exhibited her own work there by 21. (“I sold a couple of books and loved being there.”) She grew her animation talents at New York’s School of Visual Arts, where she connected with people who would lead her to become an artist on Pendleton Ward’s “Adventure Time” — which in just a few seasons has become a huge success for Cartoon Network.

Ward is a fan. “Rebecca is so caring and empathetic with her characters. She respects them and isn’t cynical with how she writes for them, which makes her characters more real, more genuine, which, I think lets her audience fall deeply into the world that she’s creating,” he says of Sugar.

At “Adventure Time,” Sugar story­boarded some of the show’s most memorable episodes, and became known to fans, too, for her scripted musical interludes (she plays ukulele and hammered dulcimer).

From there, she seems to have moved easily into her new role. “As far as being a good boss, she has a lot of respect for her crew,” her brother says. “She puts a lot of trust in everyone to bring something personal to the show. It seems to me that really helps foster a creative studio environment.”

With just days until the premiere, any trepidation appears to fall away when asked to share the best lessons she’s learned so far. How should young artists seek a break, let alone a historic breakthrough?

“Don’t wait to get permission, and don’t worry about it not being good,” says Sugar, her voice gathering with conviction. “ . . . Make it as good as you can and keep moving on. Don’t be afraid to make stuff now. You have to start immediately.”

Spoken like someone poised to shake up her “Universe.”

Steven Universe

(30 minutes) premieres Monday at 8 p.m. on Cartoon Network.