It can be "proved" even with just circumstantial evidence...not necessarily direct evidence. Murders have been found guilty even without a body as evidence.
Yes it can. And it wasn't. Just my opinion.
I won't be disappointed if she is convicted, but I won't be at all surprised if she is acquitted on the murder charges.
A hung jury is the most likely outcome though, because of the high emotion and the confusion and complexity of the evidence.
I really don't want to argue about it -- it's just my opinion.