。
She's jealous of my success.
Literal
She [topic-は] my success [object-を] is-envying.
ねたむ (also written 妬む) is the native Japanese verb for 'to be jealous of, envy, begrudge' — taking the envied thing with を. Slightly more pointed than the noun-based 嫉妬する; ねたむ implies an active emotional resentment rather than just feeling envious. The progressive ~ている marks the jealousy as an ongoing state. A vivid contrast with 成功を祝ってくれる ('celebrate someone's success'): same object, opposite feeling — and useful precisely as a counter to that warmer reaction.