Breslin plays a 13-year-old who sues her parents, former district attorney Diaz (heh) and fireman husband Patric, for emancipation because she was "conceived and underwent several operations" to help save the life of her cancer-ridden sister (Vassilieva). Dekker, meanwhile, plays the boyfriend of the older sister, who has survived his own fight with cancer.
I guess that they changed the script around in the last month? A reader pointed out when the Fannings left that the original story has the sisters a bit older than Elle and Dakota. That's not too hard to switch. However, it's a bit of a jump to add John Connor as older sis' beau. Perhaps they just made the boyfriend older (Dekker is 20), or switched a friend into a boyfriend? Dakota is mature, but not that mature! Whatever the case, the playing field is different now, and the drama is currently filming in Los Angeles.