Walter is currently performing at New World Stages and says the experience has been nothing short of exhilarating.
"I'm having the time of my life. I mean, truly," she said.
The role marks a new chapter in her career, one she describes with humor and honesty.
"The zero-Fs-left phase, doing a musical at all at this point in my life," Walter told entertainment reporter Joelle Garguilo. "Let's take on eight shows a week. It's big, it's daunting, but this is such a beloved show."
Walter said the excitement around "Heathers" extends beyond audiences to her own peers. Members of the "Abbott Elementary" cast came out to see the production, including actress Elaine Hendrix, who had never seen the original film.
"Halfway through, she's like, 'Is that guy going to, what's going to, is he going to die?'" Walter recalled with a laugh.
The Off-Broadway run comes during a hiatus between seasons of "Abbott Elementary." Walter said creator Quinta Brunson gave her simple but meaningful advice after filming wrapped.
"When we got done with the season, Quinta turned around and looked at me and said, 'Rest. Rest,'" she said.
Even as she takes on the demanding schedule of live theater, Walter is reflecting on how far she has come. Driving through Times Square, she recently spotted a billboard promoting her comedy special, a moment that felt especially meaningful.
"I literally go, these were the streets that I drove through with a baby in the back seat," she said. "I'm so lucky."
Walter hopes her journey can inspire others to pursue their own goals.
"If you're trying to make it and you're feeling down, like the world's against you, I am your inspiration, not a cautionary tale," she said. "All I can tell you is don't quit."
Her worlds continue to overlap in unexpected ways. Her "Abbott Elementary" co-star Sheryl Lee Ralph has also supported her comedy work, offering both encouragement and signature flair.
"She told me, 'Girl, it was hilarious. We're going to do a special, and you're going to come out in a gold jacket,'" Walter said, adding with a smile that Ralph is "inspirational, daily."
As for how she sums up her latest project, Walter keeps it simple: "Heathers" is "dangerous fun."