。
She was injured in the car accident.
Literal
She [topic-は] that automobile accident [in-で] was-injured.
自動車事故 ('automobile accident') is a Sino-Japanese compound — slightly more formal than 車の事故. 負傷する ('to be injured, sustain injuries') is itself formal vocabulary, the kind you'd see in news reports rather than everyday conversation; in casual speech 怪我する would be more common. The で marks the cause/occasion ('in [that accident]'), framing the event as the setting of the injury. The whole reads like a news bulletin or police report.