Hi,

My wife is currently in India and she has a valid L1 visa through her current employer. She never got a chance to travel on L1. Now she has quit the company and coming to US through H4.

Before stamping for H4 , does she need to get her L1 cancelled ?
Note : Her stamping date falls before her last day in her current company.

No cancellation stamp required. When employees leave for whatever reasons, the employer must notify immigration within 10 days, so it's automatic.