The other part of the novel that struck a chord within me was the author's description around three siblings. She speaks of this connection of three throughout the novel, and I found her descriptions intriguing.
"Rule number three: only three may play. No more, no less. Three. A number favoured as much as art as by science: primary colours, points required to locate an object in space, notes to form a musical chord. Three points of a triangle, the first geometrical figure. Incontrovertible fact : two straight lines cannot enclose a space. The points of a triangle may move, shift allegiance, the distance between two disappear as they draw away from the third, but together they always define a triangle. Self-contained, real, complete."