Gail - I agree with Jack, this looks like it is healing nicely. You could ask your vet for some Clavamox, which is an oral amoxicillan for dogs, this way you don't have to get a needle in her. But, I really think it looks like it is doing fine on its own. These types of wounds heal from the inside out. That is why you still see an opening on her skin. The tissues inside that were damaged are healing, and her constant licking is stimulating circulation. Think about you having a cut, and as it heals how it itches. The opening on the skin should be the last thing to close up. That is how you want it to be, or she might get an abcess.
As for tetanus, you can buy the antitoxin over the counter at most feed stores, you could give her a shot of that, but I really think that if you were going to have a problem, you would have already seen it. This has been several days already, and that usually has a very rapid onset.