Final answer:
There is no mention of Chencho's mother or her dying wish in 'Summer of the Mariposas', as this character does not appear in the text. The question appears to be based on a misunderstanding of the story's plot.
Step-by-step explanation:
In the context of the novel Summer of the Mariposas by Guadalupe Garcia McCall, there is no direct reference to Chencho's mother's dying wish for her son. The novel does not mention Chencho, and the provided text does not contain any details about such a character or his mother's dying wish.
It seems there might be a confusion regarding the characters and the plot of the story referenced in the question. Summer of the Mariposas is a young adult novel that follows the journey of five sisters who find a dead body and endeavor to return it to its family, touching upon themes of sisterhood, Mexican folklore, and personal growth.