“I lost this [other TV] pilot the day before the audition and I was completely ready to get out of the business,” says Underwood, 16. “I didn’t want to audition for ‘Little Fires Everywhere,’ but my mom told me to go and give it a shot and I did.

“I didn’t think I was going to get the part because … I hadn’t really done anything major before.”

On the eight-episode series — based on Celest Ng’s bestseller — Underwood plays Pearl, the rebellious teenage daughter of artist Mia Warren (Kerry Washington). They move to Ohio (Shaker Heights), where Mia encounters chatty, overbearing mom-of-three Elena Richardson. Eventually, their socio-economic worlds clash, both for Mia and for Pearl, who grows close to Elena’s teenage sons Tripp and Moody (Jordan Elsass, Gavin Lewis).

Before landing the part on “Little Fires Everywhere,” Underwood’s resume included appearances on “Criminal Minds” and “The Good Doctor.” She also played Nyla in “The Lion King” on Broadway.

“I have been doing this for five years now. It’s really hard on child actors, especially when you’re hearing ‘no’ all the time,” she says. “It gets tiring and a bit discouraging.”

‘It’s really hard on child actors, especially when you’re hearing ‘no’ all the time.’

Underwood says she learned a lot from working with Washington and Witherspoon while shooting the series.

“I would study Kerry’s facial expressions, so I was watching her religiously,” she says. “I would look in the mirror and try to copy [her expressions] since I was playing her daughter, just to make sure I had the look.

“But just working with Kerry and Reese … they were great role models to work with and to learn from,” she says. “They’re two incredibly different actors, which is something you don’t really find in the business, especially at my age.

“They were so invested in making sure that … everybody on the team looked great.”

Underwood does admit that she needed time to separate from her on-screen alter ego once filming concluded. “It took a while for me to deprogram myself,” she says. “My mom and I took a trip to Hawaii because I was so emotionally tired. It was a draining role. I would do a scene and then could not stop crying. It took like three weeks to almost a month for me [to re-adjust].”

Underwood, who already owns her own production company, “Dreamer Productions,” has aspirations to step behind the camera.

“While we were shooting, I would watch the directors to see how certain scenes were shot,” she says. “I also shadowed Meagan Good [who directed part of] a movie we shot together in 2018 called ‘If Not Now, When,’ where I played her daughter.”

And, Underwood says, she does have two other goals.

“For my dream role I would love to play Aaliyah — and I would like to star in ‘Star Wars.’ ”