The more I think about it the more everything is adding up for me.
Grace being shocked about the two babies makes sense and would give her motive to kill both Boone and Gigi.
She killed Boone because he was an unstable loose end. She killed Gigi for getting close to her father and lying about the second baby.
Grace now realizes the entire plan was built under the wrong intentions and is now trying to wrap up all the loose ends and frame someone else for the murders.
Ryan please
Plus: How did Boone know that Zayday loves eating cheetos with chocolate? Grace told him!