Somehow I doubt that Billie and SA's hobby is that of a Websleuther...
We all would have lots of hinky websites, google history, etc. if we got involved in a crime, but could also prove our involvement in this site dating back to whenever we joined. I'd be in worse trouble, as I also write novels, and have tons of notebooks filled with ideas about crimes involving missing kids, murdered husbands, etc...I have faith that LE will sort it out as far as whether or not SA and Billie are simply true crime junkies, or particpants in some sort on virtual game/life, or worse.
To me, what is relevant here is any lying that Billie has done. There is no excuse for that, no matter what, to me, when your child is missing. And yet we see it all the time...people do lie to LE, for stupid reasons, misguided loyalties, etc.
Whatever surfaces, it is clear that Billie is not the good, normal mom she presented herself to be. She moved a freak into her home who had threatened her child in some way. She knew that Hailey did not like him/was scared of him and tried to downplay that. She was putting her sexual needs above being a mom, keeping her daughter safe.