。
She trembled at the sight of the corpse.
Literal
She [topic-は] dead-body [object-を] saw-and trembled-up.
震え上がる is a compound verb: 震える ('to tremble') + 上がる ('to rise / go up'). Compound verbs with ~上がる often carry the nuance of rising into a state of intense feeling — 震え上がる ('tremble in terror'), 燃え上がる ('flare up in flames'), 立ち上がる ('rise up to stand'). The 上がる adds an upward force or peak to the base verb. Combined with 死体 ('corpse, dead body'), the sentence has a dramatic horror-story register.