In one episode, Trixie is almost about to show Timmy respect when she receives a glare from Veronica, and kicks Timmy out of her birthday party instead. It is possible that Veronica may have an influence on Trixie and wants to prevent them from getting together so that she can have Timmy for herself, but probably more so that Trixie may have not been ready yet to admit her tomboyish side.
Notably, her outfit appears to have an inverted color scheme in comparison to Trixie's. Her skirt and boots being pink while Trixie's skirt and boots are white, and her shirt being white while Trixie's is pink. The pink color of Veronica's outfit however being a rose pink, while the pink color of Trixie's is lavender pink.
Rarely does she acknowledge Timmy or his friends by name, instead, calling them "not popular kids" or losers.
In the episode The Boy Who Would Be Queen, there's a rare shot of Veronica with two pigtails instead of her trademark ponytail. While this could be a simple error, this may also imply her hair is meant to actually be in pigtails and it just wasn't shown that much.
From Season 5 to onward, Veronica stopped appearing almost completely. Even in scenes where Trixie is with her group of friends, Veronica is strangely absent. She was seen briefly in the episodes "You Doo", Future Lost", "Hairicane", "Dadbra-Cadabra" (at the school talent show, sitting near Trixie), "Stupid Cupid", and "Spring Break-Up".
It is unknown if she still has a crush on Timmy, since this sub-plot has not been referenced or supported since Season 4.
In 2 episodes, Veronica has pink eyes, although she usually has blue eyes. Her eyes were briefly pink in Scary GodParents, when Trixie introduced her to the Turners of her less precious ruby jack-o-bot costume. Veronica's eyes were turned back to her normal color when she frustratingly shined Trixie's outfit as requested. It was pink again in The Big Superhero Wish, but this time it stayed pink along with her alter ego Hawk Gal.
In Hail to the Chief, it is revealed that she wears make-up and has a pink lunchbox with a star on each side.
Many things she has are pink.
Veronica is the only female character to be seen in her underwear.
Star from Danny Phantom, another Nickelodeon series by Butch Hartman, shares similarities with Veronica. She is also considered to be the Danny Phantom counterpart to Veronica.
Both girls being popular girls at their respective schools.
Both being best friends with the most popular girls at their school who also have long black hair, wear pink outfits and makeup, and are considered to be the most beautiful. (Trixie with Veronica and Paulina with Star)
Both also being portrayed as cheerleaders. (More often in Veronica's case)
Both girls also having similar design elements.
Blonde hair
Blue eyes with multiple eyelashes
Makeup consisting of lipstick. (red in Star's case, pink in Veronica's case)
Hair accessories of a particular shape. (a flower hair clip(s) in Star's case, a star-shaped hair band in Veronica's case)
White shirts with symbols at the center. (a red "9" on Star's shirt, a pink "D" on Veronica's shirt)
There is a character from the Cartoon Network series Robot Boy, named Bambi, who bears a resemblance to Veronica. Both having blonde hair (in pigtails for Bambi's case), blue eyes, pink lipstick, pink hair accessories (a flower in Bambi's hair, a pink star hair band in Veronica's hair), and outfits consisting of a white turtleneck shirt with initial letters of their respective school (an "H" on Bambi's and a "D" on Veronica's), a pink skirt, and pink shoes (boots in Veronica's case).
Both girls being portrayed as cheerleaders in their respective series as well and using pink pom poms.
Both also being popular girls at their respective schools.
Ironically, Bambi's personality is similar to that of Trixie's.
Both girls also constantly reject or ignore the main character of their series who has a crush on them. (Tommy with Bambi, Timmy with Trixie)
Some fans believe that Veronica is secretly a fairy in disguise, because, prior to The Fairly OddParents: A New Wish, she was one of the only human characters to have pupils.
Quotes
[blinded by Timmy's shiny teeth] "My eyes! My perfect blue eyes!!"
[about Timmy's sudden popularity] "Trixie, it's a trap! See, I told you, I knew!" *Looks around crazily*
"Do I think Timmy Turner is neat? Actually, my love for him burns with the white-hot intensity of a thousand suns, but I can't let Trixie know that. [types] 'No way, he's gross.'"
"Call me Trixie! Trixie!"
"I am Trixie!"
"How many pink-hatted, buck-toothed losers does it take to screw in a light bulb?"
"I'm Hawk Gal! I can fly at speeds of 20 and 40 miles per hour and have all the powers of a hawk and a girl!"
[Timmy reading Veronica's mind] "Why isn't that loser talking to me?"
"What do you think of my new outfit? It's made of tissue paper, sugar and powdered milk!"
"I still can't see, but those two kids sound really unpopular."
"Look who decided to wear clothes today. Haha, haha! [Timmy doesn't react] Insults not working... AHHH!!!!" [faints]
