Hello. I think contacting a Trainer is a great start. Putting a muzzle on her when outside with the other dogs and buying her a outdoor kennel pen might be needed. A Vet can do a blood panel and test for lots of things and possibly might find something that could be triggering her aggressive episodes?
I have 3 bigger outdoor dogs. Maremma, Aussie/Golden Retriver and a Aussie/Border Collie. Sometimes they get into scraps and I physically have to get in the middle and I grab the aggressive dog first and pin them to the ground while I verbally scold them. I put them into a down stay and grab the other and do the same.
I hope you can find what is causing her to be aggressive before you have to leave.
I have 3 bigger outdoor dogs. Maremma, Aussie/Golden Retriver and a Aussie/Border Collie. Sometimes they get into scraps and I physically have to get in the middle and I grab the aggressive dog first and pin them to the ground while I verbally scold them. I put them into a down stay and grab the other and do the same.
I hope you can find what is causing her to be aggressive before you have to leave.