No, a freak accident would be something like she dropped the pistol, it went off and killed the husband. She pointed the gun in his direction and pulled the trigger. She may not have meant to hit him but she did - nothing freakish about that.
Also, if I read your comment correctly you're saying the family owned the dogs. They did not they belonged to neighbors. And, for a Darwin award she would have had to have shot herself, not her husband.
I had a 1st Sergeant who was as wise as he was mean and loud. One of his sayings:
"There is no such thing as 'friendly fire' - everything in front of a bullet is its enemy."