。
She has a real gift for teaching English.
Literal
She [topic-は] English [object-を] teach talent [subject-が] abundant is.
豊か ('abundant, rich, plentiful') is a な-adjective most commonly seen in phrases describing fullness or richness — 自然豊かな国 ('a country rich in nature'), 表情豊か ('rich in expression'). Pairing it with 才能 ('talent') intensifies the claim beyond just 才能がある ('has talent') to something more like 'overflowing talent.' The relative clause 英語を教える ('teaches English') sits before 才能 with no relative pronoun, modifying it directly. In a single phrase the sentence both names the field of skill and praises its depth.