I can see it was a bit cruel, and very sudden, but if she doesn’t love him, hasn’t for years so she says, there’s not a lot to discuss other than separating their finances. For all of her wittering, she does sound completely sure about the decision. It is one that can be made unilaterally. So I don’t see that she needed to consult him. Perhaps break it a bit more gently though I’m not sure how. Just do bit better than saying ‘I don’t love you any more’ and running off to The Bull.
And why doesn’t he realise the marriage is over? They did such a good job on the way this story built up slowly, it’s a shame the fell at the last hurdle as is so often the case.
And why does she insist the gambling had nothing to do with it? Losing all that money then always worrying (as I’m sure she did, she’s said so a couple of times) that he would relapse, had to take its toll. There’s a reason there are support groups for people with addictions. A lot of marriages fall apart over them. I think Shula can’t let go of her image of herself as the heroically supportive wife of the poor, troubled addict.
For all that, I can’t quite summon up as much dislike for her as for Helen - perhaps because people in The Archers can be quite hard on Shula unlike more privileged relative.