。
She has a talent for music.
Literal
She [topic-は] music [of-の] talent [subject-が] exists.
才能がある is a fixed Japanese collocation for 'to be talented / have a gift' — literally 'a talent exists.' The same shape works for many qualities: 経験がある ('have experience'), 自信がある ('have confidence'), 興味がある ('have interest'). Note that the talent itself, not the person, is grammatically the subject of ある — this is the existential-attribution pattern Japanese uses for inalienable qualities.