The natural world figures prominently in her books for children. Her love of plants and animals is most evident in her poetry, where she writes of the beauty and wonder of nature. I enjoy it. And I usually write about nature for the same reason. Also I feel that children who live in cities, and so many of them do these days, have little chance to get acquainted with nature first hand.
Books are the best substitute.
As for me, my day is not complete unless I have a good walk on a mountain trail with the dogs. Fisher is a disciplined writer. Ideas come to me out of experience and from reading and remembering. I usually rework my material, sometimes more, sometmes less. Fortunately I remember pretty well what I used to like to read, think about and do.