the first thing you need to do is take her to the vet for a full exam, including blood work and a thyroid function test. thyroid issues can lead to aggression.

Yep, what Ninapearl said. I would take both dogs in for a vet exam though. Your 7 year old male may be sick, and she's sensing it. Unfortunately, some dogs get aggressive towards other dogs who are ill.

Are all dogs spayed or neutered?

Yes they are

We had two male bird dogs. A Hungarian Vizsla and a German Short Hair pointer. Our Vizsla had epilepsy onset at 6 months, but we had it mangaged pretty well with medication. When he was about 9 months old, we got the GSP. They were best buds and never a gruff word between them. In fact, the Vizsla was very maternal towards the GSP. That changed when the GSP got a little more mature and the Vizsla would have break through seizures. When the V would seize, the GSP would attack him, biting him on the legs, more of a gnawing. When it first happened, we did not know what had happened and the vet thought he has done it himself during a seize or immediately after. Thankfully we caught what was happening the next time and we had to keep them separate from then on when not supervised. Everything was always great until the V would seize. Towards the end of his life, he had many break through seizures and it was a fight to find the right dosage to help him.

He only lived to 18 months before status epileptics took his life (we actually put him down but the vets could not pull him out of seizing and under sedation, would immediately seize when they would try to bring him out).