！
She's such a beauty!
Literal
She [topic-は] amazing beauty!
The copula だ is dropped — a hallmark of casual exclamatory speech. The full polite-ish form would be 彼女はすごい美人だ! or 美人です. Without the copula and with the exclamation mark, the sentence reads as an immediate, spontaneous reaction — the kind of thing said while looking at a photo or watching someone enter a room. すごい is technically an i-adjective meaning 'amazing / terrific / awesome', but in casual speech it's commonly used adverbially in front of a noun (instead of the grammatically prescribed adverb form すごく). 美人 ('beauty / a beautiful person') is a high-praise compound — the equivalent for men is 美男 / イケメン.