What is the plot/event in Chapter 5

During this chapter, we see Mary Alice is growing up. She sees Vandalia at the Coffee Pot Café and witnesses the cruelty of her mother. Mary Alice then determines that Vandalia needs a friend.... and she plans to be that friend. She also shows her independence by making her plan and executing it. You see how Mary Alice is similar to Grandma and growing more like her every year.

The kids think Grandma is unaware of the fact that Vandalia is hiding in Mary Alice’s room, they're wrong. Grandma even helps keep Vandalia hidden by running her mother off as well as running Junior’s parents. When Mary Alice and Joey discover that Junior wants to marry Vandalia, they set events in motion to make it happen. Throughout the story, you get the impression that all three, Mary Alice, Joey and Grandma, are each working separately but by the end of the story you see that all three were crucial in the story's happy ending.