When Shea was little, her parents weren't as emotionally there as intended for caretakers. Yes, they'd get her a thing or two if she'd asked, or it was a holiday and as tradition would give a gift. Other than that, she was basically on her own with cooking, and would have to cook dinner for them as well. Shea developed a sort of anger management problem from this, and would take it out on walls and chairs, never another being. After these anger episodes, she'd hole herself up in her room, and risk the inevitable time where her guardians would yell at her to make dinner.
Ever since she became a late elementary schooler, Shea had no memory of her past, and if she did, it was extremely foggy. Questions about herself were ultimately ignored, and anyone who was curious enough to bully her over this would be painfully corrected by her means of teaching. Shea would usually land herself in detention for this, and with no parent that cares, would stay there until the latest, because at this point school was safer than home.
Going into middle school, Shea didn't have any friends. She didn't have any idea what to do or where to go, because all of the supplies she has on her are things she's bought herself with money she stole from her "parents". Shea threw herself into clubs and electives, trying to see what was best for her. She ended up with band and ceramics as electives, and an art club after school. On the days she didn't have art club, she'd stay until the latest hours the band room could be open, to avoid going home.
Shea had the house to herself most of the days following 6th grade, due to her parents working out of home. She developed the habit of staying up late listening to music and getting homework done, because when her parents came home, she was invisible to them. Shea and her twin would work together to make life as fun as possible, after their parents took up jobs. Shiloh was basically Shea's only shoulder to lean upon for 2 more years.
When they both went into high school, they decided to take band together. Shiloh didn't take any of the electives Shea had in middle school, and wanted to be there for their sister more. They met Oberon, Eli, and Bayou at this time, and connected in the subject that they were all low-brass players. Shea and Shiloh would have near-daily sleepovers with these three, after telling them of their home situation. They were both extremely glad to have friends that not only care and support them, but even understand how they feel to a personal level.
Eli and Bayou went their separate ways with Oberon, Shea, and Shiloh after they graduated, but still kept in close contact. The three, after saying their (teary) goodbyes, decided to take their mutual skills in music, and started a band. With their respective skill, they made a very good team. One night, in a club, Shea was talking to the bartender about the music that was being played, when someone had settled themselves in the seat next to hers. The stranger introduced herself as Rosa Donahue, and had told Shea that she'd listened to the latest concert her band played, and would like to support the group. Shea had agreed almost immediately, and took in note the lady being rather young to be striking such ideas up.
After this happened, Shea and Rosa met on very good terms, and ended up befriending Rosa's good friend, Zodiac. Rosa and Zodiac were the main influencers for the band, and the other two were overyjoyed to have a good back on their journey. Shea and Rosa started going to the nightclub they met at regularly to discuss group subjects, but this later turned into more personal topics. They are now together as a couple, and the group's bond with each other is ever stronger.