。
She came home.
Literal
She [topic-は] returned-home.
帰宅する is the Sino-Japanese 'to return home,' built from 帰 ('return') + 宅 ('residence'). It feels slightly more formal than the everyday 家に帰る — more like 'arrive home from somewhere' as a discrete event. 帰宅後 ('after coming home') is a common formal-register construction in news and writing, while everyday speech leans on 家に帰った. The standard arrival ritual on 帰宅 is the call ただいま from the person coming in, met with お帰りなさい from those at home.