Jahn was born on May 3, 1938, in Moscow, Idaho, to Helen (née Schumann) and Edwin C.
Her family started visiting Monhegan Island in 1949 when her interest in art began.
She resided in Rhode Island for ten years, starting in 1966, and helped found a cooperative art gallery in her community.
In 1976, she moved to Brunswick, Maine and resided there for 12 years, whereafter she divided her time between a studio on Monhegan and Culebra, Puerto Rico.
She had college and university teaching positions in art departments in Wisconsin, Rhode Island, and Maine and in Nova Scotia and Norway.