Something that just occurred to me is if Kay had access to several of CV's accounts in order to see/find these searches/purchases then might not that potentially backfire on prosecution? I'm no expert or lawyer, but it would seem like a good defense attorney could argue that since Kay had access to CV's accounts then it's possible she could have been the one doing these searches and making these purchases in order to plant evidence or incriminate Lori of wrongdoing. Thus creating reasonable doubt.
Of course there's the problem of Lori actually wearing the ring that was sent to her as a wedding band. I'm just afraid of someone arguing that Kay's 'helpfulness' in this case could be seen as evidence of having some kind of vendetta against Lori.