What is the importance of Elizabeth's journals in the novel, All the Winters After?

Elizabeth is Kache's mother and, though she is dead at the start of the novel, her journals play an important role in the narrative. Through these journals we learn that Kache's father Glenn loved him and cared for him a lot more than Kache knew at the time. The journals kept Nadia company in her long years of isolation and she found words of encouragement in them to pursue her dreams. Through the journals we also know that Elizabeth knew Snag was in love with her, and, while she did not return the romantic feelings, she cared for Snag very deeply.