How does Squeaky’s relationship with Raymond develop her point of view in the story?

Raymond is Squeaky's older brother; however, most people think that Squeaky is the older sibling. This is because Squeaky is constantly caring for Raymond due to his mental disability:

But a lot of people call him my little brother cause he needs looking after cause he’s not quite right.

Readers do not know exactly what is wrong with Raymond, but it becomes clear that Squeaky loves Raymond very much, and she takes her protecting job very seriously. Readers get a nice image of Squeaky being a good sister while at times even being motherly due to her relationship with and care for Raymond. She is even intentional with where she allows him to run next to her. She always puts him on the safer side:

So I keep Raymond on the inside of me [...].

Readers also get to see that Squeaky is a bit of a "momma bear" for Raymond too. Squeaky is content with taking Raymond with her all over the place, but she doesn't resent it. Her job is to protect Raymond, and she is willing to do it against insults and groups:

“You got anything to say to my brother, you say it to me, Mary Louise Williams of Raggedy Town, Baltimore.”
“What are you, his mother?” sasses Rosie.
“That’s right, Fatso. And the next word out of anybody and I’ll be their mother too.”