Violet is a fairly normal girl who started her Pokémon journey along with many others in Kanto. Having been raised from birth into a society that only cared for the appearance of things, shown by the obvious preference shown for cute Pokémon, Violet accepted this as the natural way of things and is naturally drawn to cute, fluffy Pokémon. While she's not a very good trainer, she's ambitious, determined, and energetic.
Violet wanted to be League Champion ever since she first saw Red on TV. She envied him because he seemed to have retained his intelligent, assertive, and independent personality even after becoming so popular. She wanted that, and eventually Violet met with Red after he had just been released from the hospital. Overcome with envy and admiration, she fawned over him like she had seen others do. She asked him if she could travel with him for a while, and Red reluctantly agreed.
After she met Red, she caught Buzzaki, her Pikachu, who she absolutely adores and who adores her in return. The two of them are practically inseparable, and Buzzaki is very protective of her. Buzzaki's name for her is Chupika, while Radic is Chuchuka and Red is Pichupi.
When Violet met Radic, she was quickly attracted to him because of his quiet and somewhat timid personality. His resemblance to Red meant that some of her feelings towards Red, her envy and admiration, mixed with her feelings towards Radic, who tended to be Red's polar opposite in terms of temperament. She was very drawn to him, and didn't expect anything to get in her way.
Then she saw how important Red was to Radic, and her admiration quickly shifted to jealousy, particularly since Red was not treating her kindly over the course of her journey. She was resilient, but she was quickly growing tired of him and his attitude.
Radic presented a puzzle to Violet in that he was blind. She had no idea how to win his heart when he couldn't see her. She'd never interacted with anyone who was blind before, and she was frustrated and at a loss. All of them were young and emotional, and they all made rash mistakes and hurt each other. Since Violet refused to leave Red's side, or Radic's side, the three of them had a very contentious relationship in Kanto for a period. Violet resented Red for being so important to someone she loved, and she was convinced that the only reason Red pretended to care was because he liked feeling power over him.
Their arguing and fighting caused Radic to wander off more than once by himself, sparking more arguments, and things were becoming very strained at Indigo Plateau. She cared so much about Radic and he didn't seem to care about her in return, and it frustrated her beyond all measure.
When the Johto region was discovered, Radic and Red decided to renew their journey together. Violet, however, didn't have any interest in leaving Kanto for a new region (and her family wasn't about to let her either), so she stayed behind, albeit reluctantly. She didn't have much other choice. She continued her Pokémon journey alone, catching various cute and adorable Pokémon when she had the chance and mostly going through the motions since she wasn't sure what else to do.
As Radic and Red matured, so did Violet. She eventually got over her crush on Radic (realizing it was just a crush in hindsight) and began corresponding with Radic and Red on a regular basis via mail. Slowly their frayed relationship began to heal, and the three of them are now on good terms.
While Violet's superficial insistence on cute Pokémon hasn't vanished completely, as time went on she began to lower her restrictions and began catching things that she personally thought were cute, rather than going by what was commonly accepted as cute. She adores all her Pokémon and pampers them shamelessly, but always had difficulty training. It wasn't until the Hoenn region was discovered that she found her true calling.
Pokémon Contests.
When Radic told her about them, Violet knew that was what she wanted to do. Older now and still as determined and ambitious as ever, Violet opened one of the first Contest Halls in Kanto, taking the rules that Radic had given her and creating her own kind of Contests with them. Although they aren't exactly the same as Super Contests or regular Contests, they were a huge hit in Kanto. As their popularity spread, Violet became the superstar she'd always dreamed of being, this time doing something that she truly loved. The contest competitors that she met, who loved their Pokémon even if they didn't know how to battle with them, were the people she'd been searching for and never found as a Trainer.
Violet is still the respected head of a Contest Hall in Indigo Plateau in Kanto, and is famous for her routines with Buzzaki and her Clefairy. She still writes Radic and Red letters when she has the time, but she's perfectly happy where she is and very content without either of them. The three of them have become friends over the years, although long distance makes it difficult for their friendship to become very close. If they ever do come back to Kanto, Violet would be more than willing to welcome them with her best routine.
Once shallow and superficial, Violet has grown to respect other trainer's decisions about their Pokémon, and has grown up considerably. She's still stubborn and determined (similar to Red in some respects, ironically) and she'll fight until she gets what she wants, but she's very friendly and welcoming to people who want to join her Contests. They're her people, after all.
Her Pokémon are specifically trained for Contests rather than battling, and she will almost never accept a battle challenge. However, she'll take on any comers in contests. She's confident and happy, although she still doesn't like people insulting her Pokémon for any reason.
Violet appeared in Radic and Red, Continuum, and Nemo Me Impune Lacessit.
She's been mentioned in A Puppet without Strings, Veni Vidi Vici, and other fics.