Going back a bit to Hewee's testimony I don't think that has very much to do with Helen being charged with attempted murder. I think based on my considerable viewing of TV detective shows that they had to charge her with something due to the custody time limit nearly being up. They took the attempted murder option because based on the information they had at that time (stabbed Rob seriously ill in hospital, Helen having admitted to Kirsty she'd done it, no visible signs of a break in or other suspect, Helen covered in blood etc etc) and Helen refusing to talk they had no option really. Also they can reduce the charge at a later date.
I understand from the telly the CPS would already be involved at the charging stage and would look at the evidence and give advice. I think based on what they would know, and because they don't know everything we know, they would find it very hard to find another charge in the circumstances.
I'm hoping Rob being in hospital and unable to manipulate and control things is going to lead to a drip, drip of evidence that will then prompt others to start thinking and piecing things together. I bet he's been fiddling records at the shop to make himself look better and he's almost certainly been spending all Helen's money so something will come out there. I wouldn't be surprised if when winding up Berrow the auditors find errors in the records and a financial black hole. We might also get some dirt on his culvert activities. Part of Rob's nature is to control and manipulate to make himself look better and if he's not around to do it then the whole lot can quickly unravel.
Years ago when I had cause to be involved in financial crime (avoiding it and sorting out the mess afterwards, not bank robbing) there were lots of tells to look for to catch a thief: personal finances a mess, overly friendly or charming, always at work, surrounds themselves with dimwits... occasionally breathtakingly arrogant. Rob matches a few of these.