Given the task definition and input, reply with output. In this task, you're given a story (which contains five sentences only). Your task is to find all the characters which are available in the given story.

Sentence1: Allison does not like water. Sentence2: Her trainer adviser her to flavor her water. Sentence3: She took a big drink of her flavored water. Sentence4: It tasted much better. Sentence5: Allison is able to stay hydrated now.
Trainer, Allison