。
She really hates that kind of thinking.
Literal
She [topic-は] such-kind thoughts [object-を] terribly hates.
そうした is a slightly written/formal alternative to そういう ('such, that kind of') — both are pre-noun modifiers attaching to a noun directly. ひどく is the adverbial form of the i-adjective ひどい ('terrible, severe, awful'); used as an intensifier with a verb of emotion or judgment, it means 'intensely / terribly / strongly', usually with a negative coloring. 嫌う ('to hate / dislike') is the verb form — distinct from the na-adjective 嫌い ('hateful / disliked'), where the disliked thing is marked with が, not を.