Most people would be satisfied with one mystical vision. Bernadette? She needs eighteen.
This is an allusion to Saint Bernadette. Canonized for having a vision of Our Lady of Lourdes, the Catholic mystic had a total of eighteen visions in her life. Elgin references this legend by giving Bernadette an icon of the saint after she sells the Twenty-Mile House, telling her: "She had visions, eighteen in all. You had your first vision with Beeber Bifocal. You had your second vision with the Twenty Mile House. Here's to sixteen more." (2.98) It's sweet, ooey-gooey stuff.
Soon after, the Twenty-Mile House is destroyed, the family moves to Seattle, and Bernadette has a full-on mental breakdown. So what will happen to her remaining sixteen vision now? In a symbolic reflection of Bernadette's refusal to embrace her creative passions, she promises to "renounce" the rest of her "sixteen visions" if Bee will survive her early health struggles (2.206). Goodbye, creativity.
It isn't until the end of the novel that the visions reappear. Confident that they've located Bernadette in Antarctica, Elgin gives Bee the same icon along with a new list of visions to give to her mom. The first two are the same, but now there are two more added: Bee and Bernadette's disappearing act. Only fourteen more to go.
What a pitch-perfect moment. Not only is Bernadette rediscovering her creative impulses, but she's now able to integrate them into her new life. She's an artist. She's a mother. She's a master escape artist. She's all those things and more. Well, fourteen more, at least.