More than 60 residents from senior citizens to a three-month-old gathered on Sunday to make cards or posters for those affected by the Boston Marathon bombings. “Everybody feels so helpless. It’s all anybody has been talking about in town. This was an outlet for people to communicate” what they were feeling, said Robin Bellinger, who organized the event. Bellinger, an artist who graduated from Massachusetts College of Art in Boston, solicited donations including markers, paints, and glitter glue from local businesses, and town emergency responders put equipment on display. Bellinger said the mother of a three-month-old used the baby’s handprint to make a touching card.