That's not build up and all her character did is say that Lori is her real mom and that she wants to go to her. She only forgot about her for 1 scene and then went back on the Lori bandwagon. She has not asked any questions about the kidnapping at all, the situation barely even fazes her even though she should at least be curious and the show did not express any doubt/uncertainly where it would be real build up instead of this nonchalant bs and wasting screen time on her friends like the 7 minutes of Heaven bs scene. She did go into the love you more crap, in the sneak peek, she's even packing her things and still deciding on things. The build up is not sufficient because the writers didn't properly set this all up, that's why it lacks the believeability it needs to pull this off. Her character barely even cares about what's going, she's either with her dumbass friends wasting time or she's on the Lori bandwagon. Her character lacks the depth/development that is sorely needed especially with a premise like this that they've wasted. We don't see how this affects her character, the writers just lazily throw teen rebel cliches and contrived drama on her, all repeating Lori is her real mom and that she wants to be with her on a 1 track mind and the other characters pretty much go along with it.