(I don't own this picture. All Rights go to the owners.)

Name: Nega Brianna

Gender: Female

Age: Same age as Nega Ben

Appearance: Has long green hair in a braid with black hair streaks and wears a black tank top, emerald green ripped tights, a navy-blue skirt, dark purple and grey heeled boots, silver and black ear cuffs, a navy-blue zip-up hoodie, black and dark purple striped armwarmers, a dark green satchel and a black crystal pendant.

Family: Nega Ben (Brother)

Others: Second Wielder of the Omnitrix.

Sounds like Dove Cameron