。
She spoke as if nothing had happened.
Literal
She [topic-は] anything [also-も] didn't-exist [as if-かのように] spoke.
~かのように creates a counterfactual simile — 'as if,' with the か making the comparison hypothetical rather than factual. Drop the か (なかったように話した) and the meaning shifts subtly toward 'in the manner of having nothing happen,' less explicitly counterfactual. The canonical heightened version is まるで~かのように ('exactly as if'), and the present sentence carries that same stylistic flavor in compact form. The result paints her as eerily composed: she didn't ignore what happened, she rendered it invisible.