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: Gina and her friends were cleaning up their picnic. Sentence2: Her sister spilled soda. Sentence3: She should have cleaned it up. Sentence4: She only picked up the cup. Sentence5: Gina went inside, assuming the mess was taken care of.
Her friends, Gina, Her sister