Here is a story that takes after the events of Newbie Dash and 28 Pranks Later (My Headcanon) and before the events of Parental Glideance.

We see Rainbow lying on her back in her bedroom, feeling sad and betrayed of her friends playing their cruel prank on her

Rainbow: Sighs sadly

The door opens and Rainbow's little sister, Scootaloo, walks into the bedroom

Scootaloo: You feeling okay, Dashie?

Rainbow: What do you think?

Scootaloo: Right. Sorry. Stupid question.

There a small pause before the little filly spoke up

Scootaloo: Sorry about you quitting the Wonderbolts and breaking up with your friends...

Rainbow:...It's fine... Sighs again I just....I just don't know what to think anymore, Scoots... Look at me... I'm awesome, I'm 20% cooler and I've got great flying skills... And look at me now... An EX-Wonderbolt, a pony with backstabbing friends and a target for everypony to pick on...

Scootaloo: Feeling sorry for her sister Dashie...

Rainbow: It's like the whole world hates me...

Scootaloo: Rainbow Dash, that's not true... I love you, I love you the way you are and I don't want you to be anything else... You're my sister...

Rainbow: I know... You're the only one who I can trust at the moment... I can't trust anypony anymore...

Scootaloo: Isn't there anypony else you still trust, aside from me?

Rainbow: Thinks Uh.... Mom and Dad spring to mind.

Scootaloo: You never really talk about your parents much.

Rainbow: Well... We have a delicate relationship, though I love them very much and we're really close. They live in Cloudsdale.

Scootaloo: Oh.

Rainbow: They, along with you and Tank, are the only real friends I have. I don't have any another friends left...

Scootaloo: Neither do I... I still can't believe everypony did that to you...

A pause of silence before Rainbow looks at her little sister

Rainbow: Hey, Scoots?

Scootaloo: Yes, Dash?

Rainbow: Gives a small smile Thanks for sticking up for me. You had some guts telling The Blunderbolts and those backstabbers a real telling off.

Scootaloo: Smiles Well, what else was I suppose to do? Sit on the sidelines and let those ponies harass my big sister? You have always helped me before and I think that it's only fair that I help you.

Rainbow: Gives a little chuckles as her smile grows bigger United we stand...

Scootaloo: Smiles back Together we fall. You helped me...

Rainbow: And I'll help you.

Both sisters give a little laugh

Scootaloo: You don't mind me moving in with you?

Rainbow: Of course not. I could do with some company. Smiles Besides, I really would like to spend some quality time with my little sister.

Scootaloo: Touched Aww, thanks, Dashie. I'm happy to call you my sister.

Rainbow: And I'm glad to call you my sister too. Looks at the clock Well, guess it's time we get sleep.

Rainbow gets under the covers and Scootaloo climbs onto the bed and gets under the covers too. Her big sister then gives her a hug

Rainbow: Good night, Scoots.

Scootaloo: Good night, Dashie.

Rainbow then closes her eyes and falls asleep. However, Scootaloo stays awake, feeling sorry for the pony she loves

Scootaloo: In her head Poor Dashie... If I could do something for her... Hmm.... Maybe, I could... Yes! Yes, I could show her my scrapbook on her! Hm, it still needs a bit of work though... I know about her time in....THAT place, but I still need to know about her life before that... Perhaps tomorrow I could go to Cloudsdale to get some more inform. Maybe I might meet her parents too.

The little filly then closes her eyes and joins her sister in slumber

Note: For my version of Newbie Dash and 28 Pranks Later Scootaloo stands up for Rainbow. Plus, Rainbow quits being part of the Wonderbolts after the poor treatment they give her and breaks her friendship with her friends after their cruel prank (Don't worry, they get back together, but sadly Rainbow doesn't go back to the Wonderbolts).
Note 2: This scene is loosely based on this: https://youtu.be/-e64GwbTXMQ?si=irlcT9i_iX_tW_Jm