In 1987 she applied for the international course at the Clarion Workshop at Michigan State University and was accepted with a scholarship. Griffith attended Clarion in 1988.
Griffith began to write her own words for music group Janes Plane as its lead singer and lyricist in 1981. Since 1988 she has been a freelance writer. Griffith published her first novel "Ammonite" in 1993. Together with Stephen Pagel, Griffith has edited a series of three anthologies: "Bending the Landscape: Fantasy" (1997), "Bending the Landscape: Science Fiction" (1998) and "Bending the Landscape: Horror" (2001).
She has been a member of Science Fiction and Fantasy Writers of America.
As a pre-teen Griffith felt same-sex attractions, but kept it secret from her parents. To cope with it she began to drink, smoke cigarettes and immersed herself in reading and music in search of escape. She also took recreational drugs, but later abandoned all recreational drug use. Griffith was also diagnosed with multiple sclerosis in March 1993.
When Griffith was fifteen, she recognized her love for a female friend, Una Fitzgerald. After almost two years of their romance, they realized their differences, and Fitzgerald left Griffith. Thereafter Griffith met Carol Taylor, and the two became longtime partners. But they separated when Griffith met and fell in love with writer Kelley Eskridge. Now Griffith lives with her wife Kelley Eskridge in Seattle.