Sunny's parents do not like her hanging out with him; assuming that he is a bad influence on her (ironically this doesn't seem to be the case, as Sunny is shown to be a lot worse than him).
They sent their daughter to Earth as an attempt to separate the couple.
Additionally, it indicates that Predacons (specifically BB) were being "re-educated" in Maximal prisons during the Great War.
In Ultimate Alien, in her human disguise, Sunny was the spitting image of Gwen, with the exceptions of her having black hair that hung free, instead of red hair in a ponytail, and dark blue eyes rather than green eyes.
Her lips, height, and facial features were identical to Gwen's.
Doomacus • Duane • Evil Way Big • Garbage Monster • Prince Gyula • Hammer • Howell Wayneright • Hulex Colonel • Hulex Workers • Inspector 13 • Jack • Jarett • Jonah Melville • Kolar • Captain Kork • Krakken • Kundo • Lepidopterran Prisoner • Maltruant • Mino-Toga • Missy • Morgg • Mutant Seagulls • Mycelium • Nyancy Chan • Oliver Thompson • Pinky • Plant Alien • Plant Clones • Poltroon • Prisoner 775 • Red Leader • Scooter • Seebik • Solid Plugg • Ssserpent • Sublimino • Suemungousaur • Sunny • Surgeon • Tetramand Prisoner • Trans-Dimensional Monster • Trumbipulor • Violet Offenders • King Xarion • Yetta B.
Arising from the ashes of the Great War, the Maximals are the descendants (at least in part) of the Autobots, controlling Cybertron under the Pax Cybertronia.
Sunny was revealed to be playmates with Gwen in their toddler days, though the full extent of their history is currently unknown.