Jenn's Childhood

Jenn was born in Viridian City, the oldest child to Paula and Corey Greene. Corey ran an auto-parts store and mechanic’s shop on Viridian City’s east side, which had been failing for years. Paula once had dreams of being a Contest Icon, but washed out of the Contest Circuit after a few years and turned to teaching classes for aspiring Coordinators at the Viridian Trainer’s School.
Paula was very strict, forcing Jenn to behave and dress in the manner that Paula demanded, or else provoke the woman’s wrath. She tried to set Jenn up to become a Coordinator from a young age, drilling the basics of Coordinating and everything it entailed from a young age. Paula was absolutely living vicariously through her daughter, and while Jenn did as she was told to appease her mother she absolutely hated it.
As a result, she was always closer to her father. Whenever she could, Jenn would slip out and ride her bike out to her dad’s shop. She would watch him work, and did her best to stay out of the way. She didn't have an interest in cars in the slightest, but she relished the fact that she didn’t have to be at home with her mom. Corey wasn’t particularly attentive, but sometimes when he was feeling nice he would take Jenn fishing with him on the shores of Lake Viridian. Jenn loved these rare outings, and to this day has a knack for the art of the angler.
Jenn’s home life was volatile at best; it was commonplace for her parents to fight and shout at one another. She learned to tune it out, though sometimes it got bad enough that Jenn would sneak out of her bedroom window, sneak across the yard, and sit in the bushes beneath the window of the teenaged girl who lived next door. Jenn would just lie there and look at the sky, listening to whatever the older girl happened to have on the radio.
It wasn’t an easy life but Jenn managed; despite their poverty and her parents’ unreliability, Jenn still found small ways to be happy. Most often she’d go fishing by herself with the Lil’ Mantyke Fishing Rod her dad had gotten her. Sometimes she'd head to the library, or maybe off to explore the fields south of town. She knew better than to get too close to the place where the grass got really long, but she liked to get as close as she could, hoping for a chance to catch a glimpse of a Rattata or a Pidgey.
Among everything else going on, it ultimately fell on Jenn to be caregiver to Chuckie, her little brother, from a young age. Her dad was rarely home and their mom was either at work, out with friends, or sleeping whenever she was home. So Jenn learned to cook for him, made sure he was ready in the morning, and walked him both to and from school. She would check that he finished his homework, and otherwise did her best to be someone Chuckie could rely on.
Of course, that only provoked her mother more. Paula often got jealous of how close Jenn and Chuckie were, and she took those frustrations out on Jenn. Commonly, Paula would shout: “you are NOT his mother! Stop trying to turn him against me!” Jenn wasn’t trying to do that, of course, and she tried to fight back that she was only trying to be a good big sister. 
Regardless of whatever Paula screamed, Jenn eventually leanred to just take it. It wasn't like Paula was ever motivated to actually take care of Chuckie, in the end, which just forced Jenn to step in, causin the cycle to start over again.

Not Even a Note

When Jenn was 11, her father abandoned the family just before Valentine’s Day; he just packed his bags and left. He didn’t leave a note, or any contact information. Even now, six years later, nobody knows where he went. Jenn was devastated and hurt by this loss, unable to understand why her father would leave. She feared that it was because of her, and Paula—drinking and grieving and angry—always told Jenn that she was right. Paula’s behavior worsened after Corey left, reducing her daughter to tears almost every day.
The lessons and pressure of Coordinating increased. Paula pushed Jenn harder and harder, punishing her more severely whenever Jenn failed to live up to her increasingly impossible expectations. Bouts of screaming and slamming doors were provoked by the smallest infractions. Jenn struggled through it as best she could, since she didn’t really have any other options, but it took a heavy toll on her. It was this or the streets, Paula would say; "if you're so unhappy, there's the door!" 
So Jenn just took it all, going to bed in tears every night out of anger, helplessness, and a crushing despair. She was trapped and she felt like she’d never be free.