^That's fine. Differences in opinion are welcome.
She's welcome to discuss before she moves, too. Either way, we're making a lot of presumptions. Frankly, I find it suspicious that two horses are smelly from any reasonable distance. To me, that implies perhaps they aren't taking "reasonable care of their horses and property."
As far as flies, it's not unreasonable to assume it's possible that they won't be an issue. My barn has a central/timed fly spray system and they are virtually unnoticeable. So, with a little elbow grease, it's not unheard of.
As you implied, it's unreasonable to expect your neighbors to adhere to your desires. It's unreasonable to demand "x" amount years experience before moving to the country, "townie" or otherwise xD
The nature of a forum is we have to make presumptions. Horses smell of horses. Depends on which way the breeze is as to how far away you can smell them. It is more noticeable to non-horsey people and even more noticeable to horsey people when they have been scrubbed up for the city and then go to the barn/paddock. I think it is fair to assume the neighbour takes reasonable care of their horses because I believe most people love and care for their animals. I still believe neglect and abuse is way in the minority.
I might have got it wrong but I was under the impression these horses were in a paddock not a barn, so no fly spray system. It is my experience that when livestock (any) are close by a house, the fly issue increases. To what degree depends on a lot of factors. (how close, number of animals, how often pasture is cleared [horses] which would only be harrowed for cows and probably nothing at all for sheep/goats/chooks.
Obviously you can not regulate who moves to the country, but it certainly is in everybody's interest to make sure people are truely aware of the reality of it. Too often I have seen farmers(etc) pushed out because an area gets a few townies who complain and the (townie) authorities rule in their favour. It really makes me angry when the person(people) shunted out by the decision lose their livelihood, and no one has to pay them recompense.
I relocated a house one time, and the person who moved it had to hold it at his property for about four weeks (he had other houses there) and his neighbours had been complaining for some time and finally closed him down. Another house-mover had to move my house and the original man lost over $18,000 on my one deal. It is just WRONG. Not a horse issue, but same principle. I have seen it too often.
The country is peaceful, but not silent. Yet people will complain when the bulls roar and sound loud from a distance. Or the wild turkeys gobble noisily as they wander past your window. Have you ever heard a peacock? We have wild ones in some places and townie visitors usually complain they cant sleep because of them. To me, good silage smells sweet (which it should), but I have yet to meet a townie that likes the smell. . .
Not meaning 'townie' as offensive, just that the country isn't what they think it is.