There she is in the cafeteria at New York’s eastern district courthouse, when Judge Brian Cogan adjourns her husband’s trial: Emma Coronel Guzmán.

There, in the line for mozzarella sticks or a burger, are lawyers defending Ms Coronel’s husband, Joaquín ‘El Chapo’ Guzmán, the reputed leader of the Sinaloa cartel, the world’s biggest; journalists line up too, hungrier for an inside tip than anything to eat.

And there’s Emma, at the next table to us on one occasion, nibbling from a plastic container, with two lawyers who double up as soft-power bodyguards. She’ll acknowledge a smile or nod, but no more.

She was censured last week by her husband’s prosecutors for being twice in possession of a forbidden cell phone in the courtroom vicinity, and what court documents call “unauthorized” and “impermissible contact” with Guzmán. The heavily redacted papers say it was made “in concert with an attorney” – implicating the defence team.

And this week, Ms Coronel broke her silence on Telemundo TV, saying her husband was a “humble” man who wants “everyone to realize how things really are and see it all from another perspective”. The media had made El Chapo “too famous”, though: “I think he did like [the attention], he does like it a little.” “We have a business,” she said, specifying an irrigation enterprise, but “I cannot talk about that because everything in my life makes for scandal.”

In this January 2017 file photo, authorities escort Joaquín ‘El Chapo’ Guzmán, center, from a plane to a waiting caravan of SUVs at Long Island MacArthur Airport, in New York. Photograph: AP

Who is Emma Coronel, and what is her role? “It seems like the defence team is showcasing Emma and the kids in public”, says Derek Maltz, former agent for the DEA’s special operations division in New York “so people may feel sorry for this man who will most likely be in jail for the rest of his life”.

“Do these people covering the trial really believe in the beautiful love story between El Chapo and Emma?” says Anabel Hernández, who conducted a first interview with Ms Coronel in 2016. “Oh come on. She’s a distraction, and that in itself is important to El Chapo and the lawyers”. But as Hernández goes on to explain, there’s more to it than that.

Emma Coronel was born in Santa Clara, California, – a US citizen – daughter to Ines Coronel Barreras, a medium-ranking lieutenant in the Sinaloa cartel. She grew up in the ‘Golden Triangle’ of the Sierra Madre, and met Guzmán at a dance.

What followed is one of Mexico’s favourite narco-romances: Emma won the beauty pageant at a local coffee and guava festival in her village of Canelas (El Chapo present, with paramilitary entourage), and the couple was married in 2007; she became Guzmán’s third wife, possibly his fourth, though none seems to have divorced.

The marriage to Guzmán was “arranged” according to tradition, and enhanced Coronel Barreras’ role in the cartel, to run smuggling routes into Arizona. But in July 2013, he was arrested on the border at Agua Prieta, along with Emma’s older brother Ines Omar, and jailed. (Emma’s younger brother Edgar was later arrested in 2015 for aiding Guzmán’s famous tunnel escape from his shower at Altiplano jail).

In 2011, Emma, pregnant, drove to California to secure for their offspring the US citizenship she herself had acquired, delivering twins – Emalí Guadalupe and Maria Joaquína – in Lancaster.

Emma Coronel leaves Brooklyn federal court after opening arguments in the trial of the Mexican drug lord Joaquín ‘El Chapo’ Guzmán, 13 November 2018. Photograph: Mary Altaffer/AP

While El Chapo was on the run, his wife kept a low profile. She studied journalism in Culiácan; rendezvous with her fugitive husband were sporadic. After Guzmán’s final arrest in February 2016, however, that retiring role changed dramatically.

Anabel Hernández had pursued Emma for an interview since the wedding – contacts at the ceremony had reported the presence of “big politicians there, powerful people”.

“But I was told: ‘Emma doesn’t talk’ over and over”, says Hernández. “Then, after El Chapo’s last arrest, she suddenly did, for the first time” to Hernández for Telemundo and Proceso magazine. “Why? I think she had two reasons, or El Chapo did. One: as Emma said, the Mexican government wanted to kill El Chapo, and I think they did. Because of Guzmán’s friends in high government, he was dangerous, a liability. The fact that she understood they wanted to kill him, and said so publicly, made it less likely to happen”.

Hernández adds: “those government connections were part of the film El Chapo wanted to make. He went crazy and wanted to tell the whole story – something no one else wanted, in government or the cartel”. Emma’s second reason was “to ‘clean his face’. To talk about how he loves me and loves the twins, and I love him.”

When El Chapo was extradited in January 2017, Emma Coronel tweeted: “No importa lo que pase, te prometí estar siempre y aquí estoy. Te amaré toda mi vida” – No matter what happens, I promised you to be there always, and here I am. I will love you all my life.” But after August that year, she stopped tweeting (though did recently change her profile backdrop to Picasso’s Guernica). As soon as she did, weirdly, her Instagram presence intensified.

A tour of @emmacoronela is a surreal ride: there she is, apparently, taking aim in a firing range, practising; or on the beach, or wearing a bandolero-style belt. Weirdest of all is the video of a Barbie-themed seventh birthday party for the twins, with pink and white balloon arches and “Barbie Boutique”. Among her 572,000 followers is Diego Maradona, who recently took over management of the Sinaloa Dorados football team.

But here’s the twist: Coronel insists that she does not manage the account herself: “I want to clarify that I don’t have any social media sites,” read a letter to Mexican media, “and I am not posting these pages”. One post carries the confusing caption: “Solo esta pagina tengo, las demas son falsas... muchos me conocen pero pocos saben quien soy“ – “I only have this page, the others are false ... many know me but few know who I am.” A Sinaloa-based photographer, Antonio Tizoc, who posted the Barbie-birthday footage, says he did so with Emma’s permission.

“The last contact I had was in November”, says Hernández. “Emma called, late, one in the morning, and said she was worried. I asked what about? The trial? She said: ‘No, that’s okay. I’m worried about this Instagram.’ She said some of those pictures there are of Emma Coronel; some of them are pretending to be Emma Coronel. That Barbie party, she said: ‘It is the video, but I did not put it on Instagram’ – and I believe her. But if Coronel does not run the account, then who does – and why?”

“I don’t think Emma decides what to do on her own,” she continues. “I think she calls me because he asks her to talk with me. I don’t want to speculate whether Emma Coronel is in danger. But every text and message she’s sent me makes me think she really cares about the girls … she plays the part in their best interest and whoever is behind all this.”

Ms Coronel even toured the pediatric hospital in Culiácan, distributing diapers, toys and personal bathroom kits like a narco-Princess Diana. The Mazatlán Post newspaper quoted her saying: “this is done for the love of humanity, without profit, for love of our neighbor, the people most in need.”

The trial has cast dramatic light on the Sinaloa cartel’s accountancy, but mystery surrounds Emma Coronel’s relationship to the $14bn her husband is said by the US government to be worth – a reluctance to follow up on or trace El Chapo’s fortune is an emerging hallmark of the proceedings so far.

In this week’s Telemundo interview, Ms Coronel endeavored to clarify doubts about money, saying:“I have irrigation land, things like that, which I prefer not to talk about ... I do not have anything illegal. I know the government has been checking or verifying if I have something unlawful”.

A source at the New York court tells the Guardian that Coronel’s expenses are paid in cash or are ‘arranged’ payments made through “business associates or legal counsel”, and apparently legitimate. She clearly has money, yet her house in Mexico City is mid-high level, and not ostentatious.

In court, as testimony from ‘snitch’ witnesses intensifies, El Chapo meets his wife’s gaze more eagerly; behind those over-sized designer sunglasses, Ms Coronel chews gum, frantically.