。
She put aside a lot of money.
Literal
She [topic-は] a-lot [genitive-の] money [object-を] saved-up.
貯える/蓄える (たくわえる, 'to save up, store, accumulate') is more deliberate and weightier than the everyday 貯める (ためる, 'save up [money]'). The kanji 貯 itself encodes 'save' (as in 貯金 'savings'), and 蓄 carries a sense of stockpiling for future use — applicable to money, supplies, energy, knowledge, even merit. The choice of 貯える here gives the sentence a slightly literary, intentional feel: not casual penny-pinching but a planned accumulation. お金 with the お-prefix is the polite/standard form (versus bare 金 'money,' which sounds blunt or even crude in modern speech).