Hi Dorothy, It means that this female individual has a strict preference for wearing jewels that are not real. Perhaps she firmly chooses not to wear real jewels. Somehow, she only wants to wear fake jewels. Hope this helps.

看起來不是整段句子，單單看這段比較像在說是某個人或者某個報告堅持她帶了假珠寶。

她堅持應該戴了假珠寶。

Firstly, this isn't a complete sentence. It is only a phrase. In order for it to be a complete sentence, it requires a verb and maybe an object. It means that "she" insists on wearing fake jewelry. However, this sentence seems to imply something else, so adding some context (the paragraph it is in), will help others clear it up for you.