I'm actually mildly allergic to my two girls, Teenie and Tiny. They are short haired tabby cats and and I have no clue why I react to them when I don't react to my other short haired tabby cats. But because the reaction is mild and only causes sniffles and itchy skin, I don't let it stop me. They are so scrumptious I just couldn't keep away if I tried.
It sounds like her reaction is a stronger one and she's only known them for a short time so I can kind of see how she is able to make the decision. But it sad for the orangies. They are so cute. I too hope that they will be adopted out together. There isn't any chance that she will turn them out onto the street is there? It would be awful if they ended up back where they started.
Hopefully she uses the shelter that you suggested and that they have wonderful futures ahead of them with their forever homes.