She had one corroborating "witness."
A friend from her hometown who had only met her husband briefly once or twice.
She spent several weeks crying on the phone to this friend in another town, complaining of abuse.
That several week period likely coincided with her husband's increasingly pointed questioning of her over the bank statements they had begun receiving.
Establishing that timeline more closely would likely reveal that she spent weeks planning the murder.
which just shows how under brain powered the jury and prosecutor pools are.