Her 16-year-old son, Oscar Relipe Rodiguez, has to live four hours' bus ride away as Ms Grisales, general secretary of her local branch of Fecode, Colombia's most prominent teachers' union, regularly receives death threats from paramilitaries.
In her town of Quinchia in the region of Risaralda, near the Pacific coast, seven teachers have been killed in the past 10 years, more than in any other town in the region. And rural teachers are considered more at risk.
The paramilitary groups, right-wing vigilantes with alleged links to the government, target teachers on the pretext that they support the left-wing revolutionary Farc guerrillas. Ms Grisales said: "Neutrality is interpreted as backing guerrillas." Ms Grisales is on a visit to London this week, hosted by charity Justice for Colombia, to publicise the problem.
In two separate incidents in recent years, paramilitaries entered a rural primary school in Quinchia, put a gun in a teacher's mouth and told the children that if their parents support guerrillas, the same thing would happen to them. Then they shot the teacher.
The national murder rate of teachers by paramilitary forces has been rising over the past few years. In 1999, 27 were killed. In 2002, that figure had more than trebled to 83. In the first three months of last year, 13 teachers were assassinated.
More than 2,000 members of Fecode have been forced to flee their homes and house their offspring elsewhere for safety. There is no compensation or support from the government. The likelihood of finding alternative teaching is nil: recruitment is frozen because of education funding cutbacks and, of those teachers who have jobs, only 10 per cent are on full-time contracts, Ms Grisales said.
Three million children aged between 5 and 17 are out of school either because there are no places or because of disruption to their lives due to the conflict.
Ms Grisales's union and other trade unions oppose government plans, soon to become law, that will demobilise and grant an amnesty to the country's largest illegal paramilitary group, the AUC.
"We want a negotiated political settlement to the conflict which includes an agreement that will take teachers out of the war," she said. "But the government's proposed law neither punishes the paramilitaries nor provides compensation to those who have suffered."