Johnnie had a set of small volumes of English verse, extensively annotated by his own hand, which Stoddard had brought to her early in their acquaintance, leaving it with her more as a gift than as a loan.  She kept these little books after all the others had gone back.  She had read and reread them--cullings from Chaucer, from Spenser, from the Elizabethan lyrists, the border balladry, fierce, tender, oh, so human--till she knew pages of them by heart, and their vocabulary influenced her own, their imagery tinged all her leisure thoughts.  It seemed to her, whenever she debated returning them, that she could not bear it.  She would get them out and sit with one of them open in her hands, not reading, but staring at the pages with unseeing eyes, passing her fingers over it, as one strokes a beloved hand, or turning through each book only to find the pencilled words in the margins.  She would be giving up part of herself when she took these back.  Yet it had to be done, and one miserable morning she made them all into a neat package, intending to carry them to the mill and place them on Stoddard's desk thus early, when nobody would be in the office.  Then the children came in; Deanie was half sick; and in the distress of getting the ailing child comfortably into her own bed, Johnnie forgot the books.  Taking them in at noon, she met Stoddard himself. 
What did Johnnie do with the books instead of returning them?
Burned them