Lizzie and Mika taking on Ben and Billy's roll from the comics?

In the trailers there's Carol telling Lizzie to be strong. I think her dads gona die in Infected, and after his death Mika and Lizzie are going to go a bit crazy. Lizzie is seen grabbing a kinfe from Carol's hand so do you think its possible that after the prison assult (or even sooner) Lizzie might kill her little sister Mika for the simple reason that she might come back?

Tell me what you guy's think.