No, I certainly don't see any evidence that leads me to think the family could have done anything to have brought this upon themselves. And I would think the decision about guardianship or custody would be made once or if she is found alive. Is there some reason why they would have to do that now? JmoBut I don't get the slightest tick on my hinky meter where the family is concerned, do you ? Everything I have found, and everything I have not been able to find (if you follow my meaning) just screams to me that this is a normal, loving family, who genuinely adore Jayme and are terrified for her.
It's also possible that no one has petitioned for guardianship of Jayme because Denise and James had wills, and their wishes in the event of their deaths have already been made legally clear.