Don't know why everyone's surprised that she imprinted on him. Yes she's a child in terms of her age but she wasn't given the luxury to act like one. She's always had to fend for herself and lived with the reality that she's nothing but trash. Ian was the first to really see and helped her. She always had a special place in her heart and mind for him. She loves him as she does her family. Always wistfully thinking about him and wants to be together. Even when her siblings are being mean to Ian and pushing him away. She always secretly wanted him around so she pretty much imprinted long ago and the same for Ian. As many around him claimed he's changed since their meeting. The cushion in his subspace is also a testament to this change. All the destruction around yet only a single cushion appears once he met her and it continues to get fancier with every interaction.