、、。
She's rich, and what's more, very beautiful.
Literal
She [topic-は] rich [continuative-で], furthermore better-thing [topic-には], very beautiful.
Two coordinative pieces work together. The continuative copula で chains the first clause ('rich') into the rest of the sentence. Then 更によいことには ('and what's more, even better') is a written-register compound: 更に ('furthermore') + よいこと ('a good thing') + には (turning the noun phrase into a topic-marked adverbial). The whole package serves as a stylized 'and on top of that' — common in essayistic writing where the narrator is escalating a description. The construction ~ことには ('the good/regrettable thing is') is productive: 残念なことには ('regrettably'), 驚いたことには ('to one's surprise').