At the age of 15, after rehearsing in the shower, Sofia Martin made an announcement to the students at Puget Sound Community School.

“I’ve been thinking a lot about who I am,” Sofia recalled saying at the morning meeting, a daily assembly of the school’s 52 students and staff members. “I’ve come to the decision that I’m nonbinary, which means that I’m not a boy or a girl.” Sofia asked the teachers and the students, who are in grades six through 12, to use the pronouns they or them, which they promised to do.

Over the course of the next year, Sofia, who is now 18, pushed for a gender-neutral bathroom and encouraged fellow students to name their pronouns when they introduced themselves. Today Puget Sound, a small, unconventional private school in Seattle, has converted a former men’s room into an all-gender restroom and four more students have made similar announcements in front of the whole school.

“I don’t want to suggest that we got this perfectly right, although I will say that doing something was right,” Andy Smallman, the founder and director of the school, wrote in an email about the urinal.

At some schools, teaching for and about transgender people is a battle, epitomized by nationwide debates over “bathroom bills.” But at others, educators aren’t battling against trans students or their needs. Instead, schools like Puget Sound are altering their policies to include transgender kids and, more broadly, to make gender a deliberate part of the curriculum. Students are leading the way, driving schools to adopt more inclusive teaching methods.

“Ten years ago, I wasn’t really talking at all about transgender in my classes,” said Emily Umberger, who teaches health at two private schools in Charlottesville, Va. Now, “the kids are very comfortable asking questions about gender identity, transgender stuff. It’s amazing how much that has changed in a few years.”

As alternative private schools test these ideas classroom by classroom, some larger school districts are enacting them more widely. TheCalifornia Healthy Youth Act, which went into effect in 2016, requires all California public schools to teach students about gender expression and gender stereotypes. (Outside of the classroom, California just passed a law allowing a third gender option on state drivers’ licenses and birth certificates, for people who identify as nonbinary.) In Florida, Broward County requires middle school students to learn about gender identity.

Of course, not all schools or parents accept these changes. Glsen, a national nonprofit focused on L.G.B.T. issues in K-12 education, notes that in some parts of the country there are laws that forbid teachers to talk about gay and transgender people in a positive way in the classroom. Alabama, for example, requires teachers to emphasize “that homosexuality is not a lifestyle acceptable to the general public and that homosexual conduct is a criminal offense under the laws of the state.” Parents, too, can weigh in. Recently Chloe Bressack, a fifth-grade teacher in Tennessee, sent a letter to parents asking to be referred to with gender-neutral pronouns like “they, them, theirs.” After some parents complained, the teacher was transferred to a different school in the district.

But at some schools — many of them rooted in progressive pedagogy, with an emphasis on hands-on learning and social responsibility — teachers and administrators are listening when students demand they catch up on gender. Educators then have to figure out the quotidian details: Can boys wear skirts and still follow the dress code? How should teachers explain that most people with uteruses will get their periods, but not all people with their periods have to be girls? And what to do about those bathrooms, anyway?

Many educators and students noted that the goal is not just teaching kids to be accepting of trans or gender nonconforming people. Instead, it’s about loosening up the whole idea of gender, for every kid.

“This is not about those kids,” said Deborah Roffman, a teacher at the Park School in Baltimore who has been teaching human sexuality for 40 years. “Everybody in this building has a gender identity, which exists along a continuum.”

Unlike the stark sex-ed films of the past (with messages that amounted to “Don’t have sex, because you will get pregnant, and die”), today teachers read aloud from books about transgender kids (or books about gender-bending crayons or same-sex penguin dads) to start conversations. Rossana Zapf, a learning and curriculum support coordinator at the Miquon School in Philadelphia, read the elementary students Jazz Jennings’s picture book “I am Jazz,” and Michael Hall’s “Red: A Crayon’s Story,” about a blue crayon who is mistakenly labeled red.

“That reminds me of my friend,” a kindergartner said after the reading.

Ms. Umberger in Charlottesville said she uses a little game to explain the gender binary, the idea that boys and girls are opposites and that people must be one or the other. “I’ll say, what’s your favorite color? Is it lime green or crimson? And they’ll say, actually it’s royal blue,” she said. By showing that sometimes two rigid options aren’t enough, she teaches them what it means to be nonbinary.

At the Green Acres School in Bethesda, Md., students are asking administrators to rethink the dress code for eighth grade graduation, says Ann Kappell Danner, the middle school counselor. Typically, the girls wear dresses and the boys wear suits and ties. Now the students are proposing that the dress code be gender neutral: a list of acceptable clothing with no determination of which gender should wear what.

“The students are so hungry for this,” said Nora Gelperin, the director of sexuality education and training at Advocates for Youth, a Washington-based nonprofit that provides a free sex-ed curriculum for K-12 students which includes lessons about the range of gender identities. “When I’m in a school, the students are leading the way, and adults are desperately trying to catch up.”

As kids push forward, it can be difficult for even the most supportive parents and schools to know what the best course of action looks like.

A 36-year-old mother at a progressive school in Seattle, who asked not to be named because she was sharing intimate details about her young child, informed the school last year that her 6-year-old identified as a girl. The daughter, assigned male at birth, had been trying on dresses and playing around with girls’ names for about three years and she wanted to be recognized as a girl.

The teachers were 100 percent supportive, the mother says. They just wanted to know what to do. But that was exactly the problem.

“Just because I have a kid who’s going through this doesn’t make me at all an expert,” the woman said. “I kind of felt like I was drowning in information, but at the same time, very alone.”

She explained her daughter’s transition to the parents and other teachers at the school, and helped her daughter tell her class. But a year later, she still feels uncertain.

“It’s tough when people say follow your kid’s lead,” the woman said. “We’re talking about a 7-year-old who has no concept of what this looks like in the future.”

At the moment, though, even little kids are grasping the big ideas. At the Advent School in Boston, Erina Spiegelman, who is an instructional coordinator, recalled that a teacher last year asked a group of students the big question: “What is gender?”

The first answer came from a second-grader: “It’s a thing people invented to put you in a category.”