He married at 18, had a son at 19, and became a rabbi soon after.

But, for Srully Abraham Stein, the scion of a distinguished Viznitzer Chasidic family whose roots reach back to the Baal Shem Tov, it all felt wrong.

From an early age, young Srully questioned his gender, and wondered if it were possible to have a full “body transplant.”

By 19, married to a woman he had met for only 15 minutes before their wedding, and very soon a father, he was reading secular books and rebelling by breaking Shabbat.

The marriage broke up, and Stein started studying. The move to transition came in 2015, after depression forced her to confront her secret identity.

At 25, Stein — now known as Abby — has come into her own. After leaving the Viznitzer Chasidim, Brooklyn, and Orthodox Judaism altogether, Stein started the transition that’s taken her from cloistered yeshivah-bocher to transgender activist and media star.

Yet, once you talk to Stein, you realise her past might be the least interesting thing about her. It is her future that’s intriguing.

Hyper-smart and fearlessly self-possessed, Stein represents a new generation of activist, an unapologetic personality whose equal passions for Judaism and human rights make her a potent force. Illiterate in English when she left Chasidism, she’s now majoring in gender studies and political science at New York’s Columbia University.

Just before we met, Stein had spoken on seven panels at Limmud New York, more than any other attendee. “Be the change you want to see,” she told her audiences and the press. A documentary on her life is in the works, courtesy of London production company Passion Pictures. She’s been covered everywhere from the New York Post (“horrible”) to NBC News.

“Trans awareness is my cause,” Stein says confidently.

“I’m educating people, especially within the Jewish community. And I’m passionate about public policy.

“I’ve worked on a political action committee here in the States, and I’m planning to work on a political campaign.” Running for office someday is “definitely a possibility,” she adds.

Stein is both eloquent and outspoken when she fights for the cause. A few days after our conversation, she posted an impassioned dvar Torah on her blog, The Second Transition, which elegantly rolled the Baal Shem Tov, Moses, and Purim into a call for resistance against the Trump administration which had just rescinded Obama-era protections for transgender high-school students.

“This week, it felt like every transgender student has to start wearing metal pants to school — this time the regime is coming for us,” she wrote.

“The most effective path to resistance is when the persecuted, in whichever way it is, gather to fight back, together.”

Trump is “stupid,” Stein tells me. “Listening to him is insane. His speeches lack intellect.”

Two days earlier, the President had rather unenthusiastically renounced antisemitism after a spate of attacks in the US. “That came way too late,” says Stein. “It’s past talking time. The time to say: ‘We’ll pray, and we’ll be fine’ is long over. Whenever there’s something antisemitic, he takes forever to respond. Someone on TV says something bad about him, it takes him two seconds to get back on Twitter. That tells you his priorities.”

Among Jews, Stein says she’s found more acceptance — if some confusion— on trans issues.

“Among non-Orthodox communities in the US and Canada, it’s mostly very accepting, and with Jewish millennials and young professionals, acceptance is really big,” she says.

“But it’s not perfect. The American Jewish community as a rule is more progressive than the American general population, even in New York City, which is liberal and accepting. The old guard in some communities try to stick to an almost utopian version of a perfect Jewish family.”

The Union of Reform Judaism issued a ground-breaking resolution affirming the full equality of transgender people in 2015. Conservative (Masorti) rabbis followed suit with an equally forceful resolution urging synagogues to become “explicitly welcoming” to transgender people.

The resolution cited the fundamental belief that everyone is created b’tzelem Elohim — “in God’s divine image,” and referred to “non-binary gender expression” in the Bible.

In Strictly Orthodox communities, it’s a different story. “I always joked that my goal was just to get them to hate us, to recognise that we’re here,” she says. “I finally got to the point where they’re aware — I can keep talking about it, and they can’t just forget about it.”

Still, she says, “there’s no way for someone to transition and stay part of the community. And I’d be naïve to say they can suddenly change.”

Stein started a Facebook group for other Orthodox Jews who’ve transitioned, and founded a support group whose meetings draw more than a dozen people.

Even in more mainstream Orthodox communities — where, she says, institutions like Yeshiva University and the Orthodox Union officially oppose LGBT rights — “a growing number of people” are advocating for a more inclusive approach to LGBT Jews.

“There are few Orthodox synagogues where LGBT people can feel welcome,” Stein says. “But, over time, there will be more.”

With her ever-rising profile, Abby Stein will undoubtedly play a role in making that happen. “I get recognised a lot now,” she says. “I have to make sure I don’t lose track of what’s really important. When I posted a coming-out item in my blog, which I started in August of 2015, I had no idea what to expect. It went crazy. I thought I’d have five minutes of fame. But it’s only getting more intense, and it’s not blowing over any time soon. I have to make my peace with it and find a healthy balance.”

Notoriety has also brought blessings. “It’s given me opportunities I never would have had otherwise in teaching and raising awareness,” she says. “I’m going to continue to keep a public profile. It comes with a lot of anxiety, pressure and responsibility, but a lot of opportunity.”

Still, pop culture’s fascination with trans women hasn’t always helped, she says. “People exotic-ise you in a weird way. They conflate sexuality and gender, which have nothing to do with each other. If you date women, it’s like, ‘Oh, you like women, so you wanted to become one’. If you like guys, it’s ‘Oh, you’re gay, but you didn’t want to be, so you transitioned’.” Stein doesn’t discuss her personal life, and her son— now six-years-old— is off-limits.

Society also “expects trans women to be perfect the way they expect all women to be perfect,” Stein says.

“They think you’re going to have all the surgeries and operations. I know trans women who are fairly butch. I’m femme but not everyone’s like that. We have the same struggles as women, but amplified.”

With trans people suddenly in fashion, modelling agencies have even come knocking. “A few people have reached out to me for gigs. I said no to all of them,” Stein says. “That’s not what I want to get known for. Trans is still the flavour of the moment to some extent. It’ll only become stronger. When I started engaging with the trans community online, in 2012, there was almost no visibility. Now we have all of these television shows: trans supermodels; Caitlin Jenner.”

Even for someone who fights for trans visibility, this new currency is a double-edged sword, Stein says. “To some extent, it’s good. But it’s blown out of proportion and sensationalised. The stereotype used to be that every trans person was a sex worker. Now, the stereotype is supermodel. I always joke that if someone offered me a really well-paying gig, I probably wouldn’t be able to resist.”

Modelling fantasies aside, has her life gone the way she had imagined it would when she started transitioning?

“I had no straightforward vision,” she says. “I was just hoping. I’ve read a lot of David Hume. He talks about how certain people perceive religion. They can’t see beyond it. The human imagination can imagine things that aren’t real, but you need a context for it. You can’t explain colour to someone who’s colour blind. Five years ago, no matter how good my imagination was, I couldn’t have imagined how my life would be today.”

Five years ago, she says, “I couldn’t speak English. I had just found out about trans people. Now, I’m at Columbia. It’s better than my dreams. It’s better than my best imagination.”