Final answer:
The textual evidence to infer that Mary Musgrove was bilingual is mentioned in the passage. Lucy's teacher and many staff were bilingual (fluent in English and Spanish), and the district offered books in both languages.
Step-by-step explanation:
The textual evidence to infer that Mary Musgrove was bilingual is mentioned in the passage: 'Lucy's teacher and many staff were bilingual (fluent in English and Spanish), and the district offered books in both languages.' This indicates that there were teachers and staff who could communicate and teach in both English and Spanish, which suggests that Mary Musgrove had access to bilingual education. Additionally, the passage mentions that math, science, and computing were taught in both languages, which further supports the inference that Mary Musgrove had exposure to bilingual instruction. Therefore, the use of both English and Spanish by teachers and staff and the provision of books in both languages serve as textual evidence to infer that Mary Musgrove was bilingual.