Oh wow Kathy! That is a tough decision. Let's look at the facts we have before us and maybe it will help you to make a well balanced decision. When you received eggs from Andrea each time, what was the condition they arrived in? Were they properly wrapped and padded to assure a safe arrival? In other words, did her packing job look like she knew what she was doing and that it was important to her to do everything she could to get them to you in one piece?
I seem to recall you mentioning that the first set arrived all broken, or at the very least, the air cells blown out and therefore making them nonviable eggs. Was that indeed the case? The second set arrived safely enough for you to think that you had viable eggs, right? And out of that, you got two mutts?
What was the overall condition of the eggs when you received them. By that I mean, if you were going to go out to your coop and collect eggs for an incubation session, were they the kind of eggs you would have put in the incubator? Were any of them too porous to be considered for incubation? Too old perhaps? I guess what I'm trying to ask here is, what was the overall quality of the eggs to begin with?
All in all Kathy, my gut is telling me to cut ties with this gal. I just have a problem with anyone who would collect and ship out eggs, representing them as a specific breed [especially when they're supposed to be a very hard to get breed] when they know darn well that their roosters have escaped and run amok among the hens of various breeds. A conscientious and responsible breeder would have told you, when facing the replacement of the first order of eggs, that it would be awhile before she could provide you with purebred eggs again.
I know I would have been completely willing to wait the three extra weeks to assure that I was getting what I paid for. She KNEW she had the distinct possibility of mixed breed eggs, and yet she sent them out to you as purebred Coronation Sussex anyhow.
That is NOT the actions of someone who gives a rats bum about the quality of their product. Heck! She should have insisted that you wait for the purebred eggs!
Kathy, in all honesty, even though she doesn't list it as an option, I'd tell her that you want a full refund of the purchase price. You'll go ahead and take it in the shorts on the shipping, but that you want your money back. If she had been honest and upfront with you in the first place, you might have considered one more time with her eggs. But she betrayed that trust by sending you mutt eggs. And now she wants to send you two chicks, at great cost to you, along with more of her mutts, and expect that to be adequate compensation? I don't think so! Enough is enough!
Get your money back and run like heck girl!