。
She quit her job last month.
Literal
She [topic-は] last-month work [object-を] quit.
やめる (辞める/止める) means 'to quit' or 'to stop.' 仕事をやめる is the standard, everyday way to say 'quit one's job' — direct and unambiguous. In more formal contexts, 退職する (たいしょくする, 'to resign') would be used instead.