。
She lived a happy life.
Literal
She [topic-は] happy life [object-を] did.
生活をする ('live a life') is a literal, less stylistically marked alternative to the more idiomatic 生活を送る ('lead a life'). 生活 ('life, daily living') paired with する as a light verb produces a slightly textbook phrasing — grammatically fine, but biographical statements typically prefer 送る for the narrative feel of 'spending one's days.' Small choices like this build up over years to give Japanese its rhythm, and absorbing them mostly happens through volume of exposure rather than rules.