On a cool, damp night last weekend, Lauren Duca, 25, sat at a corner banquette at the Red Cat in Chelsea, sipping white wine. She had spent her day trekking around the city, getting a blowout in Chinatown, meeting some friends for brunch in the West Village and stopping home in Brooklyn for some relaxation time with her dog, a Shiba Inu puppy named Demi.

Ms. Duca was a little nervous. “I need to slow down my heart rate,” she said. She took a deep breath, closed her eyes and raised her glass. She had a big night ahead. She would be appearing on stage as a guest monologuist for the improvisation company Upright Citizens Brigade. Previous guest monologuists at U.C.B. have included Gloria Steinem, Amy Schumer and the hosts of the “2 Dope Queens” podcast, Jessica Williams and Phoebe Robinson. So, you know, no pressure.

It might surprise some that Ms. Duca — who in the past two months has gone from a relatively obscure freelance journalist to a national newsmaker — is susceptible to the jitters. On Dec. 10, Teen Vogue published a scorched-earth opinion piece she wrote titled “Donald Trump Is Gaslighting America” on its website. It went viral.