。
She rambled on for hours about the history of her family's house.
Literal
She [topic-は] several-hours [even-も] her house [possessive-の] history [possessive-の] story [object-を] tediously talked.
くどくど is a 擬態語 meaning 'tediously, repetitively, long-windedly' — it conveys that the speaker went on and on about the same topic in an annoying way. 数時間も uses も to emphasize the excessive duration: 'as much as several hours.' This is a vividly critical description of someone's conversational habits.