Kumin died Thursday, though daughter Judith Kumin said her mother was active and writing "right up to the end."
"On Saturday night she beat me at Scrabble, and the next morning she couldn't get out bed," Judith Kumin said.
Kumin was the author of more than three dozen books -- including a memoir, novels, children's literature and poetry -- the Los Angeles Times reported Friday.
Her fourth book of poetry, "Up Country," won her the Pulitzer Prize in 1973.
A poet whose work was often difficult to categorize, Kumin said one of her chief influences was British poet W.H. Auden.
Her final book of poetry, "And Short the Season," is scheduled to be published in the spring.