Gibson proceeded to the Children’s Chorus room, where two staffers welcomed her to poke through the costume racks. She admired an old hat and then gasped. “I think this was my skirt!” she said. She held up a checked skirt—urchin clothing for “La Bohème”—whose beige-and-tan print resembled the vest and pants she had on. “I must have channelled this today!” she said. What do the kids do in “La Bohème”? “We go, ‘Aranci, ninnoli! Caldi marroni e caramelle! Su, corriamo, su, corriamo! Datteri, aranci, latte di cocco, caldi marroni!’ ” she sang, in a plucky soprano. (“Oranges, trinkets! Chestnuts and caramels. Come on, let’s run!,” etc.) Also, “We had to freeze a lot.” She peered at a photograph of a city scene from “La Bohème.” “I was, like, up in there,” she said, indicating an upper level. “In a brown petticoat with the bonnet and the whole thing. I had a giant chocolate-chip cookie.”