I guarantee you if a CHILD (a small 6 yr old child, at that) was kidnapped by any group and taken across a border, the US Government would not be standing by watching to see what happens next. There would be holy hell raised and it wouldn't be kept hush-hush. The involvement would extend right up to the President, who would be in contact with the head of the other country's government. And the public would hear about it.
So far not one iota of proof that a child has ever been kidnapped by a gun smuggling and/or drug cartel group in the United States has been pointed to. "It could have happened" (because an article didn't specify it didn't) is not valid.
There could be alien abductions taking place too...I mean, hey maybe Isa was taken by a group from another planet and whisked away on their spaceship.