When Winnie takes Mae Tuck's place in the jail cell so Mae can escape before she hangs, Winnie becomes an "accomplice" to a crime. That makes her a criminal, but because she is underage, she can't be punished as an adult would be. The constable feels "she badly needed punishing," but he can only release her to her parents' custody. Winnie's family grills her about why she helped a murderer escape.
Of course, she can't explain that she saved the universe by helping an immortal woman escape an ineffective hanging and by assuring that the source of the magic water would remain secret. So she tells the part of the story she can tell—that she loved Mae. After that, her family supports her emotionally, although they still confine her to her home and yard "indefinitely." She actually becomes famous and a bit of an icon to the other children in town. One day, Winnie rescues a toad from a dog and decides to protect it by pouring the bottle of water Jesse gave her onto it. She reasons that she can always get more if she decides, when she turns seventeen, to drink the water and marry Jesse.
Readers wonder whether she did get more water and drink it. The epilogue clarifies that she did not. When the Tucks return to Treegap in 1950, they find Winnie's gravestone and learn that she died two years ago. She married and had at least one child. She never drank the water.