、。
She's rich, but she isn't happy.
Literal
She [topic-は] rich is [but-けれども], happy is-not.
けれども is the most formal of the けど/けれど/けれども series — all meaning 'but/although,' but ranging from casual けど to neutral けれど to formal けれども. Compared to the conjunction が ('but'), けれども feels slightly less abrupt and softer. Pairing wealth with unhappiness is one of literature's universal motifs — Japanese, with its abundance of contrast conjunctions, has plenty of ways to mark exactly this kind of expectation-defying juxtaposition.