。
She went there yesterday.
Literal
She [topic-は] yesterday there [toward-へ] went.
そこ ('there') is one of the こ・そ・あ・ど demonstrative series that organizes Japanese spatial reference: ここ (here, near speaker), そこ (there, near listener or just-mentioned), あそこ (over there, away from both), どこ (where). Pairing そこ with the directional へ targets the location as the destination of motion. A pared-down sentence with no detail to anchor it — the kind of testbed line that exists to exhibit basic word order and case marking.