She makes a pot of hot tea, which she knows Clark drinks with heavy helpings of sugar and milk, as a kid might. Kara lays out her Aunt Martha's quilt, so he can hold onto it if he has to.
She sits him down and he clutches the teacup with both hands, as if to warm them, even though it doesn't, while she tells him about his parents. She tells him about the things that made his mother laugh and that's when he pulls the quilt close.
When that's no longer enough, she simply holds him and lets him weep.