Knox lied to investigators during a murder investigation. She changed her story many times. When confronted with her lies, she claimed that she was all drugged up and simply didn't remember what happened on the night of the murder.
Knox, by her own actions, be they murder, falsely accusing an innocent man of murder, perpetuating that false accusation, or lying during a murder investigation, is the master of her own fate. If she was innocent and had been truthful from the outset, none of this would have happened.
The family hired the public relations firm to control the information that was released to the US public. That was done very early in the investigation into Meredith's murder. How often does the family of an innocent person hire a public relations firm to spin information such that the sole objective is to paint a justice system as medieval, unjust, backwards, persecutory and malicious. Is that what innocent people normally do? Had that PR firm been attacking a US justice system, everyone would have rolled their eyes and ignored her as a lunatic - even though there are plenty of unjust convictions in the US. Because the justice system was in a foreign country and it is understood by few in the US, the tactic worked with some (not all, by any stretch of the imagination) segments of the US population. It played into the US perspective that "everything US" is better than anything in the rest of the world. Regardless, the tactic has "fishy" written all over it.