。
She got up at 7 AM.
Literal
She [topic-は] AM 7-o'clock [at-に] got-up.
午前 ('AM, morning') and 午後 ('PM, afternoon') split the 12-hour clock in formal Japanese — though the 24-hour format (7時, 19時) is also widely used in printed schedules and announcements. The に on 7時 is required for clock times, anchoring the wake-up to a specific point. 起きる ('to get up, wake up, rise') covers both rising from bed and the broader sense of an event 'occurring' — the same verb stretches across both meanings.