It's hard to tell what's going on but I can tell you that you have done all that you can do in getting her to the vet.
At this age, there are a lot of things that can go wrong, tumors being one of them.
The risks are also high that the dog can suffer brain damage as the result of a prolonged seizure.
If you have specific questions about what's going on, please let me know. I'll tell you all that I can.
And I am very sorry for what you are going through.
