。
Seeing the dead cat gave her a chill.
Literal
She [topic-は] dead cat [object-を] saw-and shudder-felt.
ぞっとする ('to feel a chill, to shudder') is a 擬態語 (state mimetic) describing the sudden cold sensation that runs through your body in horror or revulsion. ぞっとする isn't a literal cold — it's the goose-bumpy lurch you feel at something gruesome or unsettling. In a horror movie, ぞっとする is the moment your skin crawls. The te-form chain 見て...ぞっとした links cause and reaction: 'saw [the cat], and shuddered.'