。
She gave her life for her country.
Literal
She [topic-は] country 's [for the sake of-ために] life [object-を] threw-down.
命をなげうつ ('to throw down one's life, to lay down one's life') uses the verb なげうつ ('to throw away, to fling down, to abandon'), with a sense of purposeful, dramatic sacrifice. 命をかける would be 'to risk one's life,' while 命をなげうつ is harder — it commits the act, not just the risk. ~のために ('for the sake of, in order to') marks purpose; with a person or country, it's altruistic motivation. The phrase carries the weight of wartime rhetoric and patriotic narrative; it's not casual language.