As we see in the story, Becky is a bit frighten by snakes. She is very nervous when she is almost face to face with this snake and the only thing between them is a sliding glass door. When she starts talking to Louie it would appear that Becky calms down and looks for a way to get rid of the snake. My answer is Louie helps develop the character of Becky because she seems to love her cat and talking to her cat makes her feel better and more calm.
