。
She hates running.
Literal
She [topic-は] running [nominalizer-の] [subject-が] is-disliked.
~のが+[adjective] takes a verb, nominalizes it with の, and marks it as the subject of an evaluative or emotion predicate. With 嫌い ('disliked') the frame becomes 走るのが嫌い ('hate running'). The が is required because 嫌い belongs to the special class of stative emotion predicates (好き, 嫌い, 怖い, 上手, 苦手) that take their objects with が rather than を. Productive for any activity verb.