She probably said something like "My parents said we'd be together only over their dead bodies..."
Kids do say stupid things, add hormones and things can turn tragic.
No, probably told boyfriend many a time "I hate my parents, I wish they were dead"..... like many teens do, particuarly when they stand in the way of their "True Love".......
I am not willing to say this girl is purely a victim, I've seen teenage girls (and boys too) sadly do some incredibly sick things.... and I am not on face value going to say a teenage girl who is obviously in conflict with her parents, isn't willing to plot their murders.. as sad as it is to say... that is the world we live in today.
It will be interesting watch the various gas station security cameras from their cross country trip together.
Did she have the opportunity to escape?
Was she having fun on the trip with no intent of escaping?
Second, it will be interesting to hear what the sibilings say about her actions or inaction during her parents execution.