。
She has an outstanding talent for music.
Literal
She [topic-は] music [for-に] excellent talent [subject-が] exists.
優れる ('to excel, to be superior') most often appears in its past-form attributive 優れた, modifying a noun: 優れた才能 ('outstanding talent'), 優れた作品 ('exceptional work'). The に on 音楽 marks the field within which the talent is exercised — 'in music.' The construction stacks 優れた talent (the noun phrase) onto the basic 才能がある skeleton, intensifying it.