Timantha was originally just Timmy's female alter-ego but due to a cloning problem Timantha was made as a seperate character.
Timantha wears a bright pink shirt, white boots, pink skirt, a headband with a bow & pink earrings. Like her twin brother, she has brown hair, blue eyes, and buck teeth. Her voice is much higher than Timmy's. Because she didn't have fairy godparents, Timantha stuck out like a sore thumb amongst other kids, and was bullied by Vicky on a few occasions before meeting Timmy. Originally, Timantha's voice was only slightly different from Timmy's, but as she evolved into a seperate character, her voice became much more distinct, sounding similar to Harley Quinn from Batman: Arkham series.
Timantha has almost the same personality as Timmy, except Timantha's personality is more girly & organized. She's considered smarter than her twin brother, but only a little bit. Like Trixie Tang, Timantha cares about her looks, though not on an extreme level, and has a hidden talent where she's revealed to be a good cook, where the food looks horrible outside, inside it tastes good, inherited from Timmy's mom.
Timantha gets along with her brother quite well, although she doesn't really like him at first, but eventually grew on it. Unfortunately, apart from Trixie, she didn't have a whole lot of friends until meeting Timmy & his friends. When Cosmo & Wanda reveal that she's just as miserable as Timmy, she had to share fairies with Timmy.
Tootie, oddly, is in love with her, as well as Timmy. Timantha, like Timmy in the original show, tends to avoid her.
Trixie Tang and Timantha share intrests.
Veronica is Timantha's rival. They sometimes get into risky situations.