、。
She hates fish so much she won't eat any of it.
Literal
She [topic-は] fish [subject-が] terribly disliked is, [and-で] not-even-a-bit not-eat.
A close variant of the hating-fish pattern, swapping 大嫌い for ひどく嫌い and 決して...ない for 少しも...ない. ひどく is the adverbial form of ひどい ('awful, terrible, severe') and reads as more intense and slightly more colloquial than 大. 少しも~ない is the close pair for 'not even a little' — a quantifying negative that emphasizes complete absence, distinct from 決して which emphasizes resolution ('never, by any means'). The two clauses together produce a strongly opinionated picture: not just refusing fish, but refusing every last bite.