She knew Christy heard her, but her sister ignored her, and after this was done, that fact was going to bring a fear back into Billie had been slowly dying away since she had arrived here. Christy hadn't tried to hurt anyone, and in Billie's mind, she had been getting better, coming around. After this was done, Billie was going to be scared again, scared she was never getting her sister back. Not after what those demons had done to her.
"Piper duck!" the youngest witch yelled as she was hot on her sisters trail. The fireball was already soaring, and Billie's hand shot forward, focusing her abilities on it. The fireball changed directions at the very last second, its course bringing it into a collision with a brick wall a number a yards away. The wall shook, crumbling slightly and leaving a scorch mark in the brick where the fire had hit.
The fact that Piper had tried to freeze them proved she had no idea who the girls were. And she didn't try to blow them up either, so maybe she didn't even have that power yet. Billie took one step past Christy, and then came to a sharp stop, spinning on the spot to face her sister. "What are you doing?" she half yelled, fear splattered across her face. She wasn't moving from her spot between Piper and Christy.
Instead the blonde looked up, as if expecting to see someone in front of her. "PAIGE!" the witch yelled. "Come and get your sister." she said, finishing off in a lower tone that probably only Christy would hear, since she was standing the closest. "Paige!" she yelled again, a bit more sharply before turning her eyes back to Christy, she wasn't moving from the spot, and Billie was more than ready to project the two of them somewhere to the other side of the city if she had to.