。
She was overcome by fear.
Literal
She [topic-は] fear [by-に] was-attacked.
襲われる is the passive of 襲う ('to attack, assault'), used here in its emotional sense — fear 'attacks' her. This metaphor is alive in Japanese: 不安に襲われる ('be attacked by anxiety'), 眠気に襲われる ('be hit by drowsiness'), 病気に襲われる ('be struck by illness'). The に marks the agent (the attacker — fear). This passive treatment of overpowering emotions captures the experience of being acted upon by feelings rather than choosing them — a vivid bit of Japanese phenomenology.