SUMMARY
Monteiro Lobato is still nowadays considered one of the most important authors of children'sliterature in our country. During the thirties and fourties of the twentieth century, when hewas arguably the most read and admired author for children, he corresponded with countlessreaders from all over Brazil. Through the letters we perceive many aspects of how readingwas done, the daily life of children and young people, their opinions about politics, but whatthis documentation reveals of most interesting to us is the reception of Lobato's work by hisreadership. More than that, the epistolographie with children and young people reveals howhe was attentive to the reception of his work among them and also how he modified hisnarratives, having as collaborators his own readers. In this article we intend to analyze aspecific set of letters that the writer received from a girl: Maria de Lourdes. The reader notonly corresponded with Lobato but also gave so many suggestions for his work that she became one of the characters in the work Reforma da Natureza, where she helped throughoutthe narrative the character Emília as they modify animals, plants and insects of the Sítio doPicapau Amarelo.