。
She bought a new house the other day.
Literal
She [topic-は] the-other-day new house [object-を] bought.
先日 (せんじつ) means 'the other day' or 'recently' — a slightly formal time expression. In casual speech, この間 (このあいだ) or この前 (このまえ) would be more common. The polite past 買いました is straightforward and appropriate for a conversational report.