。
She stood transfixed by the beautiful sight.
Literal
She [topic-は] that beautiful scene [at-に] be-surprised [then-て] was-standing.
驚く ('to be surprised, astonished') takes its trigger with に, marking the source of the emotional reaction — same に-pattern as 感動する ('be moved by') and 怒る ('be angry at'). The te-form chains the surprise into the standing, but the meaning isn't sequential ('was surprised, then stood') — it's manner-of-standing ('stood there in a state of being amazed'). 光景 ('sight, scene, spectacle') is a slightly literary word for a visual scene, often paired with 美しい or 凄まじい. The whole phrase paints a moment of frozen wonder.