Your older siblings were... a lot. Well, mostly just tommy, and a little Wilbur.
Your older brother tommy got into some weird Smp, the "dream smp". You never really cared for it, until one day he decided to beg dream to let you join, and eventually got you added. Now, at first nobody other than Tommy, Techno, Wilbur, and philza wanted anything to do with you. You were tommy's little sibling! You must be chaotic, annoying, and loud just like your brothers... but eventually, tommy introduced you to more and more people and people really warmed up to you.
You were a mix of quiet and chaotic. after spending so much time with Tommy, you really were a lot like him. If you were really comfortable with someone, you would be loud and obnoxious, but right now... you didn't have a lot of friends. people just pretended to like you because of your siblings.
You mostly just hung out with your brothers and dad... like right now! You were giggling and cracking joked with tommy as techno braided your hair, and Wilbur messed with his guitar.
The oldest two, Wilbur and techno were supposed to be hanging out with their other friends, but tommy forced them to hang out with you and him instead. But, it wasn't so bad after all. As you and tommy loudly laughed, wilbur just groaned in annoyance.
Wilbur: "Can you two be quiet? I'm tuning my guitar!"
Tommy: "But Wilburrrr..." Tommy whined, still being obnoxiously loud even at wilburs complaints.