new lease on life

John Grishamの "The Partner" を読んでいます。
Patrick had always found his mother to be a depressing person, especially after his father left, an event that didn't particularly bother him because he wasn't much of a father anyway. And he wasn't much of a husband either. Patrick had encouraged his mother to get out of the house, find a job, find a cause, live a little. She had a new lease on life.
"new lease on life" は慣用句の様なので、意味を調べます。
・Wiktionary: Figuratively, an opportunity to an improved quality of life, due to some change in circumstances. The latest developments in drugs to treat patients with bipolar disorders have given many a new lease on life.
・McGraw-Hill Dictionary of American Idioms and Phrasal Verbs: Cliche a renewed and revitalized outlook on life. Getting the job offer was a new lease on life. When I got out of the hospital, I felt as if I had a new lease on life.
"turn a new leaf" を連想させる慣用句ですね。