。
She's a credit to the school.
Literal
She [topic-は] school [possessive-の] honor is.
学校の名誉 ('the honor / pride of the school') uses 名誉 in its sense of 'honor / credit / reputation' — a noun that can describe both the abstract quality and the specific person or achievement embodying it. Saying someone *is* the school's 名誉 frames them as a living source of the institution's good name. This is the kind of phrasing used in school newspapers, alumni speeches, or graduation addresses — slightly elevated, with the polite です fitting the formal feel. Compare with 誇り ('pride'), which is more inward-looking ('something one is proud of'); 名誉 leans outward, toward how others perceive.