In 1982 human rights campaigner Rosario Ibarra became the first woman and first political outsider to stand for president in Mexico. Her presidential bid was a direct challenge to the country’s long-established male-dominated political system. Ibarra’s motivation to stand was both political and highly personal: she wanted to draw attention to the country’s ‘disappeared’ political prisoners, among them her own son. Mike Lanchin talks to her eldest daughter, Rosario Piedra.