What is the main conflict in Drowning Ruth by Christina Schwarz?

One winter night Mathilda Neumann drowns in the icy waters of Wisconsin. Her daughter Ruth remembers drowning as well but has been told all her life it didn’t happen. Drowning Ruth’s vocal narrative of several main characters slowly develops the truth behind that icy winter night while shining a light on the secrets of family and friends that her Aunt Amanda has been guarding since Ruth was a child.