Oh gosh ....That must make her miserable.Dexter gets really bothered by them but landing on his body ,he gets disturbed by every one.I was recommended a horse product I'll have to go and have a root around to try and find it.It didn't work for us bit might be worth a try ...or something similar if you google horse fly products quite a lot of things come up x
I use Farnams when we take a walk in deer fly season. It's a roll on so I can put it exactly where I want it on his face with no fear of it getting into eyes. It's not tested for humans but I put it on me too because once the flies find him unappealing then they go for me. I wash it off both of us when we get home. I wouldn't want it on all the time. http://www.farnam.com/all-products/fly-insect-control/roll-on This is for horses, ponies and dogs.