。
She stays calm during earthquakes.
Literal
She [topic-は] earthquake [possessive-の] time calm is.
地震の時 ('at the time of an earthquake') uses とき without に — both forms (with and without に) are natural for temporal clauses. 落ち着いています ('is calm') uses the polite progressive of 落ち着く ('to settle down / become calm'). The sentence describes a personality trait — she maintains composure in a situation where many people would panic.