There are so many questions about this earlier incident. It doesn't make a whole lot of sense, but then, we aren't getting much of the story, are we?
The only part that does make sense to me is if Huckaby was using this as a trial run, as a "testing" of the drug and its effect on the children.
There are too many unanswered questions about this. I keep thinking about the neighbor's comment that the FBI told her not to talk about it. Someone said the FBI was brought in when Sandra went missing, as it was a possible kidnapping. I get that, but why would they still be involved? Did the Tracy PD ask them for help? That would be smart, as this is looking like a complex case on some levels. But why is the FBI talking to neighbors about the earlier "drugging" incident from Jan. and telling her not to talk about this? That child wasn't missing long enough for the FBI to be brought in THEN. So it would seem they're asking about that NOW, in the Cantu murder. That's the part that I find puzzling.
For now, we don't actually know that Huckaby did take either or both children to the park in January and not somewhere else, as someone has pointed out, like to the empty church. We don't know that she did or didn't drug either or both children. We don't know what the drug was, how long or how much she gave the child, if she gave it to her.
We don't know when the child was returned exactly, and if she was "sleepy" or "napping" and that might have delayed the mother's alarm. Did Huckaby actually take the child and put her to bed in her home, laughing with the mother at the "mistake" and talking about how hard the children played and how tired the children were? We have no idea, because LE isn't telling us.
I find it way too suspect in the light of Sandra's murder to not think Huckaby did drug that child and somehow managed to get away with it. I also now suspect that Huckaby has been involved in something making her own child "sickly". Maybe Huckaby found out, like Casey Anthony, that drugs are "Zany the nanny". Of course, I'm speculating here, of course, but I find these "coincidences" of drugged and sickly children around Huckaby too sinister now to think they're not related.