Who gifts Elphaba with her broom in the novel, Wicked: The Life and Times of the Wicked Witch of the West?

Elphaba's broom was a gift from Sister Yackle in the Mauntery.

In Wicked: The Life and Times of the Wicked Witch of the West by Gregory Maguire, Elphaba receives her broom as a gift from Madame Morrible. Madame Morrible is the headmistress of Shiz University, where Elphaba studies, and she gives the broom to Elphaba along with the suggestion that she pursue a career in sorcery.