Serafina Pekkala is the queen of the witch clan. She's hundreds of years old, but like a Twilight vampire she still looks young and fabulous. She was formerly in love with the gyptian elder Farder Coram. The two had a son, who died. Her daemon is a goose who can travel very far without her, and who helps Lyra free the severed daemons from Bolvangar.
The conversation between Serafina Pekkala and Lee Scoresby in Chapter 18 is an important one. Serafina argues for the role of fate in the events unfolding around them. In her mind, individuals don't have much of a choice about the role they play in life. Serafina is a contrast to Lee, who argues for free will, individualism, and choice. Notice how Serafina argues her point:
Perhaps we don't mean the same thing by choice, Mr. Scoresby. Witches own nothing, so we're not interested in preserving value or making profits, and as for the choice between one thing and another, when you live for many hundreds of years, you know that every opportunity will come again. (18.13)
How does Serafina's semi-immortal state shape the way she sees the world?