Welch's film career began in Italy starring opposite Virna Lisi. She starred in Ron Howard's Cocoon and its sequel, Cocoon: The Return, in which she portrayed an alien. She played the part of Princess Rosebud in the Golan Globus adaptation of Sleeping Beauty.[2] Returning to Europe, Welch worked mostly in Italian and German film and television productions. She appeared in American independent films I Shot Andy Warhol, Sue, and Search and Destroy. She portrayed the role of Catherine Powell in the 1996 video game Ripper.
Welch posed on the cover and a nude pictorial in the November 1995 edition of Playboy. Welch appeared in American Vogue, Italian Vogue, British GQ, Interview, French Marie Claire, Italian Moda, and German Bunte magazines.
