The short answers are the writers fault. I've become very irritated with the character as she is a right little bitch. Even more than most teenagers I know. But her voice is very monotone.
I agree. I am so tired of hearing that little bastard say "you're not my mum." Not once have I ever heard Jane say she was their mum. The writers have done a great job of making the character into a little Pauline.
Maybe now after what Steven did she'll calm down a bit but then again I thought after the incident with Craig she would calm down. I guess I am the eternal optimist.
As far as casting on looks goes, the actress who plays Lucy definitely looks like she could have been Cindy's daughter. The EE staff got that one right. Unlike the current Steven, who used to be blond and also passable as Cindy's child!
What has disgusted me about her is she was more worried about Steven than her father or even Jane being shot in the gut. She's Cindy's spawn all the way.