。
She was hurt by what he said.
Literal
She [topic-は] his [genitive-の] words [because-で] mood [object-を] worsened.
Same 気を悪くする idiom, but with で marking cause instead of に. The two are subtly different: ことばに気を悪くする focuses on the words as the trigger; ことばで気を悪くする frames them as the cause/reason. Often interchangeable in practice; here で is slightly more analytical, に slightly more direct.