Born in Ribe, Andersen matriculated from Ribe Cathedral School in 1981. She went on to study Italian literature at Aarhus University and Siena University, graduating in Italian poetry in 1990. In 1996, she became editor of Hvedekorn, an important Danish literary journal.
After her debut with Dicentra Spectabilis in 1991, she translated poems by Giuseppe Ungaretti into Danish. Hew own symbolist poetry is suggestive, evoking nature and hardly imperceptible mood changes in human relationships. Some of her poetry has been translated into English by the American poet Thom Satterlee (born 1967).