、。
She used to live a lavish lifestyle.
Literal
She [topic-は] long-ago, extravagant life [object-を] did [used to-ものだ].
豪勢な生活をする means 'to live a lavish/extravagant lifestyle' — 豪勢 (ごうせい) means 'extravagant' or 'luxurious.' The ~したものだ pattern (past + ものだ) expresses nostalgic recollection: 'she used to live lavishly (looking back).' This is the same reflective ~たものだ pattern, carrying a sense of 'those were the days' or 'that's how things were.'