“Let’s figure out what our letter of the day is!”

Ms. Rachel, the children’s YouTube star, cooed that sentence in an Instagram video posted this week as she dug into a sensory bin of purple rice, with the kind of texture toddlers tend to ogle.

Set against a blank yellow screen, like many of her videos, she smiled as her ponytail bobbed onto her signature pink T-shirt and blue overalls.

She gasped as the camera panned to a bright red “N” in the rice.

Holding the letter, she cheerfully told viewers in her singsong voice that her videos would soon be available on Netflix.

The announcement is the latest development for the booming empire of Ms. Rachel, the child educator from Maine turned viral video star, whose appeal has been compared to that of Mister Rogers and Beyoncé.

She has more than 13 million subscribers on her YouTube channel and millions more on Instagram and TikTok, with her videos have collectively drawn billions of views.

Ms. Rachel, whose full name is Rachel Accurso, also has a multibook deal with Random House; a line of toys, including a popular cooing doll in her likeness; and branded T-shirts, pajamas and bathing suits. She works with her husband, Aron Accurso, the co-creator and co-producer, and they are represented by the powerhouse talent group Creative Artists Agency.

“We’re so happy that our videos will be reaching more little ones and their families through Netflix,” Ms. Accurso and her husband wrote in an email. “It’s the best feeling to see families singing the songs, using the learning techniques and creating meaningful moments together beyond the screen.”

At Netflix, the videos join a lineup of children’s programming that already includes fan favorites like “CoComelon” and “Blippi,” which also found fame on YouTube.

The four-episode season of “Ms. Rachel” will be available to stream starting Jan. 27, and it will include 30- to 60-minute lessons that teach numbers, letters, colors and shapes. More episodes will be available later this year, and her videos will continue to stream on YouTube. (Representatives for Netflix declined to comment.)

Ally Shuster, Ms. Accurso’s agent at CAA, said she learned about the Ms. Rachel videos two years ago through her young nephew, Oliver, who was mesmerized.

“I think people respond to Ms. Rachel’s passion and authenticity,” Ms. Shuster said in an email.

“Rachel and Aron put so much thought and care into their content,” she said, adding, “Their love for children and their work really shines through, and I think that’s a big part of what makes them so successful.”

Before she found fame on YouTube, Ms. Accurso, 42, earned master’s degrees in early childhood education and music education, and worked as a music teacher in the Bronx.

She left the job to spend more time with her son, Thomas. Around his first birthday, she started making videos for him when she noticed that he was behind on speech development. She and her husband uploaded the videos to YouTube in 2019, and the content struck a chord with young children and their parents.

Speech pathologists have said that her videos incorporate techniques used by speech therapists, such as speaking slowly and repeating simple sentences. Many parents have said the programs feel more wholesome than other options.

(The American Academy of Pediatrics recommends that children under the age of 18 months avoid screen time, children between 18 and 24 months limit screen time to educational programming watched with a caregiver, and children over age 2 limit it to one hour a day of high-quality programming.)

To the parents who have watched Ms. Rachel’s rise on social media, the Netflix deal is welcome news for a variety of reasons.

Betsy Tannenbaum, 35, an attorney in Nashville with two young children, said she discovered Ms. Rachel after noticing a group of children who were transfixed by her videos at a birthday party.

“My husband and I are both working parents, and we work from home, so screen time is sometimes unavoidable,” she said. “Ms. Rachel makes that as guilt-free an experience as possible.”

Ms. Tannenbaum also thinks watching the videos on Netflix will streamline the experience.

“The current platform she is on can sometimes feel convoluted with unrelated content and suggestions that can be distracting to both myself and my toddler,” she said, “and can sometimes get us down a rabbit hole.”

Avery Adrien, 34, a content strategist living in Richmond, Va., also has two young children and said Ms. Rachel’s videos were part of her family’s evening routine.

“We appreciated that it was a very relaxing show,” Ms. Adrien said. “A lot of kids’ shows these days are overstimulating.”

She and her husband found Ms. Rachel’s videos on YouTube several years ago. Ms. Adrien said her family felt like they grew up with her and were excited about her success.

“Ms. Rachel’s in her bag, getting that money,” she said, “and we think no one is more deserving of it than her.”