Amy Schwartz, prolific author and illustrator of books for children, died Feb. 26 at her home in Brooklyn. She was 68.

Her books included several on the theme of “100 things,” written in rhyme — 100 things That Make Me Happy, 100 Things I Love To Do With You, 100 Things I know how To Do. Among her most recent books was 13 Stories About Ayana, a follow-up to her 13 Stories About Harris from two years before. To fit 13 stories into a book for an age group with a notoriously short attention span required that some be decidedly spare. One story in the “Harris” book was just one sentence: “Harris was standing on his truck and he shouldn’t have been.” It was accompanied by two illustrations: Harris on his toy truck, and Harris in a heap beside it, crying, after it had tipped over.

“Amy was an acute observer of all the tiny details that together make up a child’s life,” said Mary Cash, vice president and editor-in-chief at Holiday House, one of her publishers.