Tā zàishì de shíhou, shì yī wèi zhùmíng de zuòjiā.
When she was alive, she was a famous writer.
Tips
usage
在世 is a polite, literary way to say 'alive.' In everyday speech, 还活着 (hái huózhe) is more common. 在世 is often used when speaking respectfully about elders or the deceased.
