Ava has the video and Ric saw Kristina at the crash site. That doesn't bode well at all for Kristina. Ava wanted her divorce settlement back right? Alexis wasn't thrilled when she was named executive of the estate--until Ace is 18. Why not relinquish the role? Let's say that Ava's divorce settlement from Nikolas was $5 million. Sonny is a multi-millionaire. Tap him for the money and then Ava would be paid off instantly vs installments and Alexis could tell Ava: "Sorry. I'm no longer executor. You'll have to deal with Sonny."
But nah, these writers took the most illogical plot point-heavy path forward.