The questions raised by SCHMAE really interested me.
"I wonder, is obstructing justice a separate charge from giving false information?"
I'm not a lawyer, so I did a little online checking.
On a very shallow level it seems that obstruction is not at all the same as, and is certainly not limited to, giving false information to authorities.
The term I looked at, obstruction of justice, in the USA refers more specifically to the crime of interfering with the work of a police investigation or of prosecutors or other officials.
In Canadian and English law, however, it is a common law offence which seems to be broader in its scope. To paraphrase my source, in Canadian law, obstruction of justice would describe the actions of any person who has knowingly attempted (or conspired, or intended) to thwart, corrupt, or prevent justice being served whether to one's self, or to another party. This would include such acts as intimidation or hiding evidence. (Side note: in Canada this crime carries a maximum sentence of life imprisonment.)
I wonder if lawyers would agree that this could mean that making a false statement to police would not necessarily rise to the level of obstruction, and so police needed to cover all bases by having separate charges. There seem to be many subtle ways in which a person could try to influence the course of an investigation in one's favour. IMO, LE has now accumulated enough kinds of evidence to build a solid case against SK as well as AS. Also, IMO, it hints that other charges could be forthcoming against SK, AS, and other adults present in the house at the time of Elaina's "disappearance".
It's a more distant possibility that when other people with knowledge about this case learn that these charges have been brought against SK, they will realize that the same charges could apply to them. This could push them to bring what they know to LE to forestall further action.
This is jmo, and should not be taken in any way as legal advice. I do find that the differences in meaning for the same term in different jurisdictions is fascinating and hope that someone with a background in law will clarify any errors I may have made.