Should a bomb-plotter's wife turn supergrass?

Liquid bomb plot wife Cossor Ali 'did not warn police'

This is a tricky one for libertarians and all others who no longer have a naive trust in the State. Should a wife be expected to act as an informer against her husband?

I thought that under English law, a wife is not a compellable witness against her husband in most criminal cases, although a change in the law of Scotland was proposed in 2006. If she cannot be forced to testify against him, why should she be expected to act as a spy or agente provocateuse?

Is this another way in which the State can use a hard case to make a bad law? Is this part of a general modern assault on the natural law of family, so that the State (and, eventually, the Party) will reign supreme in all things?