Lisa - (Aussie Girl)
I don't think we can really understand the psychological control such an evil person has over their victim. Abused in every way plus the inherent threat of doing the same to someone she loves... it makes perfect sense that she felt trapped and couldn't escape without chilling consequences.
Sandra Hoover
I think she "could" have escaped - but she'd seen firsthand how evil this man was. She knew he'd follow through on his threats to harm Macy. Saving her sister is what kept Mallory in line and mum. He seems to have eyes and ears everywhere - even in the police dept.