Glen has frequently undertaken massive, innovative international projects - she was the first foreign woman to direct at the 14,000-seat Epidaurus amphitheatre in Greece, where she directed Prometheus in Greek. (This production also toured Greece and Canada).

In 1979 she founded the Chung Ying Theatre Company in Hong Kong and opened the Queen Elizabeth Stadium with a musical version of her adaptation of Animal Farm in English and Cantonese. Later she helped steer the company to independent status with its own Board of Governors. She directed many English and Cantonese-speaking productions integrating both British and Chinese cultures. Productions played major venues in Hong Kong and toured throughout South East Asia.

In 1986 she was invited to Japan to create a popular performing 'house-style' and direct Rhyming Theatre Company's annual Shakespeare productions. (With Japanese actors, directed in Japanese) She adapted Japanese translations, incorporated facets of Japanese and English culture, introduced actor-musicians and made full use of flexible space. Much Ado About Nothing (1986) Comedy 0f Errors (also toured Japan 1987) Measure For Measure (1988) Merchant 0f Venice (Best production award 1990) As You Like It (1992) Macbeth (1994)

Other productions in Japan include Educating Rita - Theatre Project Tokyo Benisan Pit.
Merchant of Venice, Blood Brothers (premiere and three subsequent revivals) Shochiku Company Ltd. Sunshine Theatre, Aoyama Theatre (Tokyo) Nagoya Theatre (Nagoya), Minamiza Theatre (Kyoto) - (all in Japanese).

Glen has also directed for Vienna's English Theatre - Midsummer Night's Dream, As You Like It, The Dresser and Skylight. Her most recent production for this theatre was directing her own adaptation of A Portrait of Dorian Gray.

She directed Gilbert and Sullivan's HMS Pinafore which was the first in-house production for the 1,800 seat theatre at the Mondavi Centre, Davis, California, U.S.A. She then returned in 2005 to do a production of The Rocky Horror Show

She directed a new production of Blood Brothers for Fuji Television Network for the Aoyama Theatre, Tokyo and Osaka.

In 2005 she directed a massive sell-out success with 'Grand Hotel' for Fuji Television Network, Tokyo and returned in 2007 with a new musical - 'Titanic The Musical' and , Two Gentlemen of Verona.

2007 brought Glen to Barbados with Blythe Spirit and in 2008 a production of Macbeth.

2009 saw a revival of 'Titanic The Musical' and 2010 brings a return to Seoul, Korea to the Seensee with her own adaptation of 'Two Gentlemen of Verona'