。
She lived up to our expectations.
Literal
She [topic-は] our expectations [target-に] responded-to.
期待にこたえる is a set expression for 'to live up to / meet someone's expectations.' こたえる here is the verb 応える ('to respond to, to live up to') — distinct from 答える ('to answer a question') despite the shared kana spelling. The に marks the expectations as the target the response is directed at. The kana spelling こたえる leaves the sense ambiguous on the page, but context disambiguates: with 期待 as the object, only 応える makes sense.