。
She led a lonely life.
Literal
She [topic-は] solitary life [object-を] sent.
孤独 ('solitary, alone, lonely') is a heavier word than 寂しい — 孤独 names the existential state of aloneness, while 寂しい describes the feeling of loneliness. The pair runs through Japanese literature: 孤独 in the title of Kawabata's novellas, in 田山花袋's character sketches, in countless contemporary essays on modern alienation. 生活を送る ('lead a life') is the standard biographical-frame collocation, with 送る ('send') taking on the figurative meaning of 'spend, live through.'