。
She already knew the story.
Literal
She [topic-は] already that talk [object-を] was-knowing.
既に ('already') is the more formal, more written counterpart to the everyday もう. Both translate as 'already' but the registers differ: 既に shows up in news, business writing, and slightly elevated speech, while もう dominates casual conversation. 知っていた ('was knowing' = 'knew') uses the resulting-state ~ていた: in Japanese, 知る ('to come to know') marks the event of acquiring knowledge, so being in a state of knowledge requires ~ている. Bare 知った would awkwardly imply 'came to know at a single moment.'