、。
She fainted, but came to a few minutes later.
Literal
She [topic-は] consciousness [object-を] lost [but-が], several-minutes after [at-に] sanity [to-に] returned.
数分後 ('a few minutes later') gives the time interval, with 数 ('several, a few') prefixed to a counter as the standard way to express a small unspecified number. 正気に戻る ('return to one's senses, come to') uses 正気 ('right mind, sanity, consciousness') paired with 戻る ('return') for a vivid, narrative phrasing of regaining consciousness — more colorful than the clinical 回復する. The に on 数分後 marks the point in time, and the に on 正気 marks the result-of-change goal.