Her performance won the Best Actress prize in the 2005 BAFTA Cymru awards, defeating expected favourite[4] Billie Piper (who had been nominated for her role as Rose Tyler in Doctor Who).
In 2012, she starred in her co-written one-woman play Who's Afraid of Rachel Roberts with Dave Ainsworth in a touring production for the Torch Theatre Company.
[9] Griffin's first short play, Killjoy, was written for Theatre West Glamorgan (subsequently renamed Teatr na n'Og) and was first performed in 1993.
[10] In 1997, Griffin collaborated with Jo Brand on a short play, Mental, which was based on their shared experiences as psychiatric nurses;[2] the two performed an updated version at the 2003 Edinburgh Festival Fringe.
Griffin adapted her script for Flesh and Blood into the screenplay for Little White Lies,[13] which was filmed on location in Cardiff and Swansea and premiered in the UK on 10 January 2006.
[16] In 2006, Griffin was arrested for daubing red paint on the National Museum of Wales as part of a protest against Israel's actions in Lebanon.
Meanwhile, Kai Owen, who starred alongside Myles in Torchwood, called Griffin "a wonderful, wise and inspiring woman" and stated that "Wales has lost a powerhouse".
[19] In a post on Facebook, Twin Town director Kevin Allen wrote: "Helen was a fantastic actor and a terrific writer, she was deeply principled but approached everything she did with a twinkle in those gorgeous, sexy eyes of hers."