It sounds more like a Coyote than a fox to me.
I am firmly of the opinion that pets are not entitled to freedom at the expense of wildlife. If it were up to me, I would even go so far as to say that a backyard with cats isn't qualified to be certified as wildlife habitat. Trapping and relocating wild animals so pets can roam free and kill other wild animals is simply not a viable option. You can build an enclosure for your cat so she can be outside but separate from wildlife.