？
Where did she go?
Literal
She [topic-は] where [to-に] went [question-の]?
に or へ both work for marking the destination of going; に is a touch more conversational, へ slightly more written or emphatic about the path itself. The の at the end signals an explanatory question — 'so where did she go, then?' rather than a flat 'where did she go.' Sentence-final の in casual speech invites a fuller backstory than the bare interrogative.