Dedham resident Diana Marrero was recently awarded the 2012 Sue Heilman Award for Excellence from the nonprofit Horizons for Homeless Children. Marrero has been a teacher at the organization’s Schoen Family Community Children’s Center in Dorchester for 13 years, and is known within the organization for her energy and problem-solving skills. “Diana is eager to learn and deepen her knowledge of child development and best practices,” the agency’s announcement on the award said. “She has a profound respect for the parents and extended family members, and works closely with them to ensure that the children in her care thrive and grow.”