Why is Alexandra Breckenridge in the main cast?

I mean, I've seen the first seven episodes, and (LITTLE SPOILER) she is only in the first three, not talking nor moving in the second one, and her storyline sounds like over (it's a pity. I wanted more from her...). Why is listed in every single episode? And she is listed before the daughter, and Elliot is not in the main cast... I think it's weird.