The car thing brings up another point. If her mother is wealthy, why was Mackenzie driving a decade-old car?
If I remember correctly, the parents were putting one son (possibly two?) through college. I'm sure no one would expect the son to quit college so that his tuition money could go toward the reward fund.
I'm just surprised that no businesses or corporations in the area have put up reward money. Where I live, a woman was brutally murdered, and many, many businesses came together to immediately offer a reward that's now in the 50K+ range. Her family didn't put any money toward the reward... businesses realizing that as long as one is not safe, none are safe, put the money up. Hate that the same thing isn't happening in Washington.