。
She was hit by a car.
Literal
She [topic-は] car [by-に] was-hit.
車にひかれた is the passive of 轢く (ひく, to run over) — she was run over by a car. The に marks the agent (the car) in the passive construction. This is a standard passive, not adversative, though the result is certainly negative. ひく can be written in kanji as 轢く, but the hiragana form is common for this sense to avoid the relatively rare kanji.