Take her outside late in the afternoon or when it is slightly overcast and meter off of her fur. If you are indoors, you can point your flash to the ceiling and again, meter off her black fur.
These black dogs are even a bit tougher, as you have to not only expose for black, but white. I tend to expose for the highlights and pull the midtones up in photoshop if needed
You can see in this one I blew the highlights on the nose. I can live with it but technically it is wrong
Again, a tough exposure as there is black and white and shadows. Metering for the white is still the safest. If you blow the highlights, forget it
This was done on an overcast day, which is like a giant softbox in the sky.