[1] The oldest daughter in a family of migrant farm workers whose parents had emigrated from Mexico, she was born Guadalupe Alcala in Oklahoma.

In 1937, she moved to Chicago, where she married Andres Reyes in 1939 and settled in the Hyde Park neighborhood.

[1][2] After developing spinal meningitis soon after birth, her son Bobby was left mentally and physically disabled.

Unable to find suitable care facilities for her son, she started a support group in her own home for children who had developmental disabilities.

[1][2] Reyes helped lead the push for a new high school in Pilsen, later known as Benito Juarez Community Academy.