You know, when I first read your first post, I was horrified that someone would do something so nasty to you. But after thinking it over, I actually think a miscommunication might have happened.
At first I was trying to understand why a woman with a flock of her own had enough eggs to send to you for hatching, but not enough eggs of her own for eating. It doesn't make a heck of a lot of sense why she'd want to ask someone else for eating eggs. What's the point of having a flock then?
It is entirely possible that she thought you were doing an equal trade of FERTILE eggs. That would make a whole lot of sense, because she can add genes she's admired in your flock, and you can get genes you want from hers. If you thought she only wanted eating eggs, and gave her unfertile ones, she might have spent all that time trying to incubate them.... ending up with nothing.
Now I personally, in her shoes, would expect my kind and fair-minded neighbor to compensate me for all the duds in some way. A very self-centered person might have demanded all of the chicks, but if what I suspect is happening, she thought the fairest solution is to divide the hatch.
I would be very careful about this conversation you're going to have with her, because if the above is true, you would look deeply petty and mean by sabotaging her with all roosters, or lying about your hatch (which she might find out later just counting your chickens over the fence that look like hers).
I'm sure that just by talking it over, you two will realize it's a miscommunication, and all laugh about it later. Maybe over tea while watching your flocks.
Just a thought!