" If they would also refuse to use lethal force to defend their wife of children then yes they are moral cowards. Motive is everything"
Why lethal force? There are other options so why would they be moral cowards if they chose a different option rather than lethal?
What if the husband was not in a position to defend the family but the wife had a gun and chose to injure the attacker rather thang kill him, but it wasn't enough, would she also be a moral coward?
What is acceptable or expected from a male in relation to wars is generally not the same for a female or in defence of their families. We should not be imposing our personal standards of moral cowardness on all males, either by law or judgement.
Motive is everything and we expect a different standard from males and females in general.