。
Despite her success, she wasn't happy.
Literal
She [topic-は] succeeded [despite-にもかかわらず] happy was-not.
~にもかかわらず means 'despite' or 'in spite of' — a formal concessive pattern. 成功した (succeeded) sets up the expectation of happiness, which にもかかわらず contradicts. 幸せではなかった is the negative past of 幸せだ (happy). The sentence captures a common theme: external success doesn't guarantee inner fulfillment.