I also wish they would not just toss characters into a movie then toss them out. Pretty annoying, though I do like the two characters of Tria and Tricia as well. They were, likely, originally plot devices, like other characters have been, but handled better then some other plot device characters.
Likely she'll be less speciest and such then Cera since she may have the influence of more then just her father around. Would be interesting if she grew the backbone to be one of the few not afraid to tell someone, even her father, when they are wrong.