There is a significant amount of evidence that incriminates WA, but it is largely circumstantial and thus, potentially, more defendable. So the case against her is complex and I'll be the first to admit that I don't know how that evidence will hold up in court.
CA and DA had evidence such as the various text exchanges, CA giving money to KM, DA and HA doing the money drop, DA's flee attempt etc That strength of evidence does not exist for WA. Playing the devils advocate, WA's 18 min phone call to CA on the morning of the murder could have been about anything. Her drive up Trescott was a regular route she took. JL confirmed this.
The State's challenge will be to show how this regular route was suspicious. Bring in the lies, the fact it was not a shortcut, it was timed shortly after the murder, liquor store was out of the way etc Trescott is an important piece of evidence, but I can see how Lauro could easily put doubt in the juries minds.
Based on what we know, I could understand why the State might choose not to indict WA. It's certainly not a slam dunk case. But I think there is more evidence that we are not privy to. I think CA has an axe to grind and will cooperate )if the opportunity presents itself). Ultimately, I think GC can present a narrative that establishes WA's guilt by carefully stepping through the events from when WA first left Dan to the present day. Once presented to the jury, this narrative could prove beyond a reasonable doubt that, at the very least, WA knew Dan was going to be killed.
There is simply too much circumstantial evidence to suggest that WA was not entirely ignorant of the crime. This does not mean she is necessarily guilty of an offence, but it brings her a step closer. Lauro can present a scenario in which WA was aware of the impending murder but was not a party to the crime, that is, she did not want Dan killed. However, if he attempts to argue that she was completely ignorant, he will be laughed out of court.
I've always maintained WA's best defence will be she somehow got wind of a plot to kill Dan, a plot that was carried out behind her back. She panicked in the LE interview/was in shock and could not bring herself to believe CA and DA had killed Dan. It was not until years later she finally had the strength of character to admit to herself her family had carried out this heinous act.