。
She has a good eye for art.
Literal
She [topic-は] picture [object-を] see eye [subject-が] exists.
目がある, attached to a noun-modifying clause like 絵を見る, is the idiom 'to have an eye for X / to have good judgment about X.' It's one of a rich family of Japanese body-part idioms — 口がうまい ('smooth-tongued'), 手が早い ('quick-handed'), 耳が早い ('hears news fast'), 足が長い ('travels far') — where a body part stands in metaphorically for an ability or trait. Here 目 ('eye') stands for discernment in visual or aesthetic judgment, and the whole expression praises someone's taste or critical sense.