。
She took the matter to court.
Literal
She [topic-は] that matter [object-を] court-matter [into-に] made.
裁判沙汰 ('court matter, lawsuit affair') is a noun for the unfortunate state of having a dispute escalate into a formal court case. The 沙汰 component once meant 'message, news, judgment' (still seen in 警察沙汰 'a police matter', 刃傷沙汰 'a bloody affair'); coupled with various heads it now generally connotes 'situation that's gotten out of hand'. The ~にする pattern marks the result of an action — 'made [the matter] into a court case'. Japanese culture historically prizes resolving conflict outside the courts, so 裁判沙汰にする often carries a faint note of 'this should not have come to this'.