My wife has been fascinated by this case and listens to the daily podcast about it. She's gone from "oh she definitely did it" to "maybe she's innocent, I can't be say beyond reasonable doubt" after this week's testimony. So Erin is clearly doing some good for her case on the stand.
I haven't been following the case closely, but I listened to one recap podcast a week ago where they describe the multiple phones, the missing phone seen on camera that wasn't provided, with the one provided to police being factory reset first, and taking her dehydrator on CCTV to the tip after telling police she didn't have one - it was all pretty damning.
She keeps asserting her lies until she gets completely cornered by the evidence and then changes the story and comes up with some excuse for the lies. Excuses like, oh I was embarrassed, oh I got confused, etc. I think she did it.