I would like to expand on my earlier thoughts now that I am at a computer. I hope that I am not violating any rules by my post, as it is my own opinion and pure speculation/hypothetical.
From what I personally know about the FLDS, it is very hard to be a male within the community. Obviously less men are needed and wanted since they practice plural marriage. Unfortunately, it is not uncommon for young men to be pushed out of the community (for various reasons) as they grow up.
So imagine being a mother of a son - one with a potentially unknown future. Imagine the (potential) desperation you would feel knowing that that is their future. Not every member of the FLDS believe the doctrine to the same degree. The majority don't know any different way of life - they were born and raised within the community. They don't leave CC often, and when they do they don't socialize with the outside community members. However, some have successfully permanently left/escaped the FLDS and want nothing more than to help other family members within the community escape. But that is very difficult.
There are literally people within CC that police the grounds. They have strict curfew and it is not easy to come and go. Another poster speculated that several people could be the father of or related to Jerold. Some of those people are in trouble with the law and one was even deceased. Those two situations could be difficult to the mother. She could be forced to "marry" another man. What if that was the situation and she was feeling desperate for her children (not sure if she has other children or not).
And she saw this camping trip as the perfect scenario to get Jerold to safety. Like I said earlier, I imagine that while camping they are able to let their guard down a bit and have some more freedom. She may have anticipated this and arranged a family member (outside of the community) to come get Jerold. Since his "leaving" would not be approved, she had to set the stage that he disappeared. Once someone had safely taken him, they would have had a chance to get away before she reported Jerold missing to the group. And then they searched personally for 4 hours (which seems like plenty of time to find a boy who had just disappeared) And likely, she has no idea what type of search effort would take place (from outside CC) to find Jerold. Afterall, she has most likely been sheltered from the "outside world" her entire life. So she doesn't understand (or didn't at the time) that the "outside world" would literally call in the troops to look for her son. And now what happens? Is he found safely with another family member and returned to CC?
Again, I hope (in a way) that this is what happened. But it could mean big trouble for her (both outside and within CC) if this is the case - and that isn't ideal either.
I hope that little Jerold is alive and well - wherever he is.