。
She was utterly astonished by the news.
Literal
She [topic-は] news [at-に] extremely was-surprised.
The cause of 驚く ('to be surprised') is marked with に, not を — Japanese consistently uses に to mark the trigger or stimulus of an emotional reaction, the same に that appears in 喜ぶ ('rejoice at'), 怒る ('get angry at'), 慣れる ('get used to'). 非常に is a formal/written-flavored intensifier ('extremely'), stiffer than とても.