I understand everybody's issue with Carter but she is a teenager who world got torn apart. To her the kidnapper is her mother and her "family" are total strangers. She looks at her family as the one who took her mother from her so I do not think she is going to automatically like them. She sees them as people who turn her world upside down. Her kidnapper groom her and she believes her kidnapper loves her and gave her an amazing life. She needs to see her mother as a kidnapper first before she can except her family.