A teacher in an Atlanta suburb has been fired for reading a book to fifth-grade students that explores gender roles and identity through the eyes of a child who describes their shadow as purple, her lawyer said on Friday.

The Cobb County Board of Education voted 4-3 on Thursday to approve the recommendation by the superintendent, Chris Ragsdale, to terminate the contract of the teacher, Katherine Rinderle, according to a recording of the meeting.

“The district is pleased that this difficult issue has concluded; we are very serious about keeping our classrooms focused on teaching, learning, and opportunities for success for students,” the Cobb County School District said in a statement on Friday.

The statement said, “The Board’s decision is reflective of that mission.”

Ms. Rinderle, 33, was a teacher at Due West Elementary School in Marietta, Ga., which is northwest of Atlanta.

In February, she purchased “My Shadow Is Purple,” by the Australian author Scott Stuart, at a district-approved book fair, and read it to her class on March 8.

The book centers on a gender nonbinary theme in which a child describes the color of their shadow as different from their mother’s pink shadow and father’s blue shadow.

In an interview on Friday, Ms. Rinderle said the students discussed the book, in which the child enjoys toys and sports commonly associated with either boys or girls. Then they were encouraged to write poems describing their own “shadows.”

“The book was a picture book about a child who had many different interests,” she said. “They were really able to relate to the importance of belonging.”

After she read the book, she received emails from some parents who complained, while others told her they appreciated its message affirming people’s differences.

“What the district has decided, unfortunately, is truly not representative of all parents’ viewpoints,” she said of the firing.

In June, Mr. Ragsdale said in a letter to Ms. Rinderle that the district intended to terminate her employment for “insubordination, willful neglect of duties and any other good and sufficient cause,” a copy of the letter said.

It said the “controversial” topic of gender identity and fluidity was “not an appropriate” topic for 10- and 11-year old students.

It included objections that she told the class to use “they” and “them” pronouns when discussing the book in class, and it objected to her use in class of another children’s book written by Stacy Abrams, the Democrat who ran against Gov. Brian Kemp in 2022.

In a two-day hearing last week, a panel appointed to review the case agreed Ms. Rinderle had “neglected her duties and that there was sufficient cause to take action,” but it rejected Mr. Ragsdale’s recommendation to fire her, her lawyer, Craig Goodmark, said in an interview.

The Board of Education, however, voted along partisan lines on Thursday, with three Democrats opposing her termination and four Republicans approving.

Cobb County was once reliably conservative but has undergone a demographic and political shift. It voted for Joe Biden by 14 percentage points in 2020 and Democrats swept major countywide races, though they have yet to capture control of the county school board.

During the public comments, parents and educators touched on parental rights, inclusion and trust in teachers.

One man, wearing a shirt that read “Ban Bias, Not Books,” said he and his wife tell their child to “be kind to everyone, always.”

“That is what inclusion is all about,” he said. “It isn’t about indoctrination or grooming.”

Another parent said the school must communicate with parents before the discussion of some topics, including sex education.

The decision reflected several laws signed last year by Gov. Kemp.

One law, the Parents’ Bill of Rights, “provides greater transparency to parents and legal guardians regarding what their student is being taught in school and protects the fundamental right of moms and dads across this state to direct the education of their child.”

Another law is meant to prevent “divisive concepts and ideologies from invading the classroom.”

Mr. Goodmark said the laws “have operated to censor teachers in the classroom.”

Ms. Rinderle can appeal to the state Board of Education or possibly take other legal action, he said.

The Cobb County School District has more than 106,000 students, making it the state’s second largest.

The public comments at the board meeting echoed some of the debate in schools across the United States, touching on privacy rights, parental consent, reading materials, sports teams, bathroom use and dress codes.

The American Library Association, which curates lists of the most challenged books every year, said that before 2020, most complaints came from parents who wanted to remove or restrict access to a book.

Since then, there has been more evidence of a “growing, well-organized, conservative political movement” attempting to remove books about race, history, gender identity, sexuality, and reproductive health from public libraries and public schools, it said.