。
She began a new life.
Literal
She [topic-は] new life [into-に] entered.
生活に入る (せいかつにはいる, 'to enter into a life') is a somewhat literary way to describe starting a new phase of life. The spatial metaphor of 'entering' a life treats it as a place one moves into. More natural alternatives exist (新生活を始める), but this phrasing has a deliberate, formal tone.