The Naval Criminal Investigative Service led by Mark Harmon's Gibbs was introduced during JAG's eighth season, and they soon earned their own solo series.
NCIS got off to a slow start but over time became one of the most popular procedurals on television. This is likely down to the show's likable cast of characters, including Ziva, McGee and Abby.
Maybe the actor could be persuaded to make a cameo whenever NCIS finally comes to a close, but it's doubtful she would ever return to the series full time.