。
She dropped out of school.
Literal
She [topic-は] school [object-を] quit.
やめる ('to quit / stop / give up') is a high-frequency verb that ranges across many domains: タバコをやめる ('quit smoking'), 仕事をやめる ('quit a job'), 学校をやめる ('drop out of school'). 学校をやめる specifically tends to mean 'drop out / discontinue one's education,' as opposed to 学校を卒業する ('graduate'). Being a 中退 (literally 'mid-withdrawal,' a school drop-out) carries social weight in Japan's credentialism-heavy society — particularly for high school and university — and the verb やめる is often tactfully avoided in formal contexts in favor of more neutral phrasing. The を marks 学校 as the thing being abandoned.