She was the daughter of a wealthy merchant and was known for her great beauty. Her name means "one with the hue of the blue lotus".
She suffered from a horrible family life, she was kicked out of her house, and eventually she met with great poverty and had multiple marriages to try to get out of her poverty. Eventually she found her own daughter (whom she thought was dead in her second marriage) married to her final husband, and the thought that she shared a man with her own daughter sickened her so much that she sought refuge in the Buddha and became a nun.
Samyutta Nikaya V.5, the Uppalavanna Sutta, is attributed to her:
Then the bhikkhuni Uppalavanna, having understood, "This is Mara the Evil One," replied to him in verses:
Though a hundred thousand rogues Just like you might come here, I stir not a hair, I feel no terror; Even alone, Mara, I don't fear you. I can make myself disappear Or I can enter inside your belly. I can stand between your eyebrows Yet you won't catch a glimpse of me. I am the master of my own mind, The bases of power are well developed; I am freed from every kind of bondage, Therefore I don't fear you, friend. Then Mara the Evil One, realizing, "The bhikkhuni Uppalavanna knows me," sad and disappointed, disappeared right there.