There are multiple ways to locate bilingual education materials for children.
Try using the keywords: "bilingual" or "bilingual books" or even "parallel text." You can also try searching as a "subject" search, with phrases like "Spanish language." Remember to always limit by location to Teaching Materials Center. You can keep limiting further by topic, genre, or language. Sometimes a book will not be under the heading of "bilingual" but in the "more details" tab it will say something like "text in English and Japanese" (for example).