。
She has a refined manner.
Literal
She [topic-は] elegant attitude [object-を] is-doing.
態度をしている ('to have a manner/attitude') describes someone's habitual bearing. 上品 (じょうひん, 'elegant, refined, classy') is a na-adjective that describes polished, tasteful behavior or appearance. The polite ~ています form suits the sentence's theme of refinement.