But she was no patsy. Those who knew her said she was 'beautiful but evil'. Behind the false poses of compassion lurks a 'demon' who would think nothing of snatching her enemies from their beds in the dead of night and revelled in the fear her name evoked.
It was Pineda who ordered the cartel and corrupt local police force to abduct 43 student protesters on September 26 to prevent them from disrupting a celebration she had planned in the town. She wanted them to be 'taught a lesson'.
Members of the gang have apparently confessed to murdering the students, incinerating their bodies after 'stacking them like a grill' and disposing of their remains in a river.
To them, Pineda was known as 'Jefa de los Jefes', which means Boss of the Bosses.
'Maria de los Angeles Pineda was the principal director of criminal activities committed by the Guerreros Unidos cartel', a spokesman for the Mexican Federal Attorney's office said after the arrest of Pineda and her husband.
The gang members have not only confessed to the students' murder, but to many more disappearances and homicides in the Iguala region since Pineda and her husband came to power two years ago.
Pineda is now facing charges of homicide, association with organised crime and the forced disappearance of 43 students.
One of five children, all of Maria's immediate family is now either dead or behind bars because of organised crime.
She is the second daughter of Salomon Pineda and Maria Villa, who together came to forge a brutal and widely feared family crime syndicate operating in Guerrero and Morelos states, which lie to the south of Mexico City.
Their rise to power came when Pineda was still a young girl and she witnessed the kidnapping, ransoming and eventual murder of her elder sister, Guadalupe, by the Familia Michoacana cartel.
Determined to seek revenge, the family partnered with a rival cartel, cementing their hold and widening their reach.
'The Pineda-Villa family would always leave their victims' bodies by the dock on the town's lagoon', said fisherman Valdemar Servin, of Zihuatanejo, Guerrero, where the family had their headquarters. 'But they paid off the local authorities and made sure people who spoke out against them disappeared'.
'Maria was well known around town', he added, 'and she loved the fact that people were scared of her'.
Maria met Jose Luis Abarca in his father's wedding dress shop in Iguala, where she was visiting with her mother to sell wedding dresses to the businessman. The couple were married less than a year later, both in their mid-20s.
'That wicked woman corrupted my brother. He was always ambitious, but he was never evil', said Roselia Abarca, the sister of the Iguala mayor, in a telephone interview with the MailOnline. 'He knew when he met her that she was part of a dangerous family but he always said he was marrying her, not her brothers'.
'Now it turns out she was the worst of the whole lot.'
'Jose Luis's job before he met Maria was selling straw hats on the Iguala streets', said Roselia, who still lives in her family's hometown.
With the Pineda-Villa capital behind him from his partnership with Pineda, Jose Luis Abarca launched himself into the gold business, establishing jewellery stores around Iguala and the wider region.
They soon became known in Iguala as the 'Imperial Couple' because they came to own more than 17 separate jewellery shops and private homes around Iguala.
In 2009, Pineda's parents were convicted and imprisoned for involvement with organised crime.
Three months later two of her brothers, Alberto and Mario, were murdered as a result of gang violence.
The murder of Pineda's brothers, who were powerful members of Beltran Leyva, caused a rift in the cartel, which split into separate sub-cartels.
One of these was Guerreros Unidos, established by the only remaining members of the Pineda-Villa family, Pineda and her brother Salomon.
Their organisation quickly took control of northern Guerrero state. Extorting local residents and paying local police forces for their complicity, Pineda and Salomon quickly gained a fearsome reputation for brutality.
Shortly after establishing Guerreros Unidos, Salomon was arrested in northern Mexico for drug trafficking and spent four years in federal prison. Pineda was left in sole charge of cartel operations.
Pineda's cartel became infamous for dead-of-night disappearances, during which criminals or corrupt police officers would silently enter victims' houses during the early morning and kidnap them straight from their beds.
Their victims would sometimes return badly beaten, but at other times never return at all.
'People who spoke out against the Pineda-Villa family here would suddenly go missing and you'd never see them again', Iguala resident Luis Figueroa Hernandez told MailOnline. 'We all knew who was responsible, but no one could say anything because the same was guaranteed to happen to them'.
Since the disappearance of the students, search parties from around the country have combed the countryside around Iguala for them.
The concerned residents have not come across the students, but in the process of searching have discovered over forty mass grave sites, where victims of Pineda's cartel were murdered.
'The graves are very shallow and we haven't found a single one that could be more than two years old', search party leader Crisforo Rodriguez told MailOnline, 'that's the same amount of time that those two were in power'.
'What's quite clear is that the people discovered in these clandestine graves have clearly been marched to the site, forced to dig their own graves and then killed', he said, speaking from the Iguala town centre where his search party was preparing to continue their search for the students. 'While others it seems have been buried alive'.
'This cartel has a terrible reputation for brutality that is only now coming to be recognised'.
'This town used to be a peaceful place where people weren't afraid to step outside', said Bertha Salgado, a resident of Iguala for over sixty years, 'but now our police are murderers and our government is made up of delinquents'.
Many of the town's residents see Maria as the driving force behind the Imperial Couple's criminality.
'She was like a demon', said Esther Vargas, Iguala's head of economic development who worked closely alongside Pineda in the municipal government. 'She had a very short temper and would become very aggressive when she was angry'.
'She was beautiful and evil, like a soap opera villain', said Jorge Salgado, another Iguala native. 'The entire town was terrified of offending her for fear what might happen'.
The Mexican federal attorney's office recently announced that after coming to power in 2012, Jose Luis Abarca began to make monthly payments of between two and three million Mexican pesos (£90,000 - £140,000) to his wife's cartel, which would in turn pay every official from the state district attorney's office downwards in order to attain immunity for its actions.
The abduction and murder of Arturo Hernandez Cardona in 2013, Jose Luis Abarca's greatest political opponent in the region, is a case that has yet to produce any convictions, despite multiple leads and compelling eyewitness testimony.
Nicolas Mendoza, the only surviving member of the ordeal, told MailOnline: 'Myself and eight other protest organisers were intercepted by armed members of the Guerreros Unidos cartel on our way back from the protest. We were taken to a shack outside the town and tortured for two days, after which Jose Luis Abarca arrived'.
'He asked why Hernandez Cardona persisted in annoying him, and then finally said: "Now I'm going to give myself the pleasure of killing you"'.
According to Mendoza, the Iguala mayor took a shotgun and blasted Hernandez Cardona in the chest. His body was found strewn on the main road south of Iguala five days after his abduction.
Just a month before his murder, Hernandez Cardona had been harangued by Pineda in a political debate during which he had attacked Mayor Abarca for his questionable ethics.
Pineda had stood up from the audience and shouted that Hernandez Cardona and his party were a 'group of criminals', and chillingly, that they 'were going to get what they deserved'.
Weeks later all the eight major figures of Hernandez Cardona's opposition Unidad Popular party were either dead or had disappeared.
Despite the overwhelming evidence, the case has never come close to a conviction.
'We took Nicolas's testimony to both the state and federal prosecutors, but in the end they said they would not convict Abarca of any crime because he was a public figure', said Sofia Mendoza, the wife of Hernandez Cardona, who has been fighting for justice ever since her husband's brutal murder.
'Over a year and a half later we still have no knowledge of what occurred on that day', said Mario Castrejon, the Iguala municipal police administrator. 'But we must leave the prosecutors to their work'.
'We live in a system where the guilty and rich get away with their crimes, while the innocent and poor are persecuted and murdered for speaking out against the corruption', said Crisforo Rodriguez, a local political activist.
The probable murders of the students have sparked protests around the country. In recent weeks tens of thousands of others in have taken to the streets of Mexico City and the southwestern state of Guerrero, where the students were abducted, to condemn the government's handling of the case.
It the toughest challenge yet to face President Enrique Pena Nieto, who took office two years ago vowing to restore order in Mexico, where around 100,000 people have died in violence linked to organized crime since 2007.
A mob of protesters set fire to the wooden door of Mexican President Enrique Pena Nieto's ceremonial palace in Mexico City on Wednesday.