What 3 moments/passages in Lucy Gayheart connect and talk about Lucy's relationship with her father and sister?

Lucy Gayheart and her sister, Pauline, are at opposite ends of the spectrum when it comes to self-fulfillment and family responsibility, much of which concerns their widowed father. Because their mother died, the older sister plays the maternal role: that is Pauline. Her conflict with Lucy centers on Lucy’s being spoiled, especially through receiving music lessons. Lucy’s father, however, supports her interests and backs her studies in Chicago.
In book I, as Lucy is catching the train to return to Chicago after a break, the tense relationships among Lucy, Pauline, and Jacob are conveyed. Jacob knows it will annoy Pauline if he shows too much affection toward Lucy, and Pauline is described as being “in a fret.”
In book II, when Lucy returns home after Sebastian’s death, it is clear she will remain at home. Pauline is less than kind and understanding. Willa Cather tells us, “In her own way Pauline loved her sister, though there had been moments when she certainly hated her.” She continues, “Lucy had never been aware of any of these hidden feelings in her sister.”
Finally, it is an argument with Pauline that precipitates Lucy’s death. Upset by their disagreement over money, Lucy leaves the house and goes to skate on the river, where she falls through the ice and drowns.
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