Dd is also very allergic to cats, but moreso if she touches them or in a multi cat household. She can cat-sit, like, run in, dump some food, pet the cat, come home and wash up, and is ok. But in our friend's home, with several cats(it fluctuates, she is a rescue person) and dd is congested, flushed withing 30 mins without antihistamine. So, we can never get a cat, and she and I like them. She also wants a career in animals. Oh, she has reacted after 5 minutes in a large Petco around here too, where they board pets, including cats. The only visible animals of any kind were behind glass, seperate from the store, but clearly on the same air system. We had to leave.
CM, she always tested postive, but as long as we owned the one cat she was with since birth, until 3yo, she never reacted. Reactions began a couple fo years after that daily exposure was over. Makes me wonder if she is a good candidate for allergy shots, as she is now developing nasty other EAs.
I hope it all calms down for oyur dd, CM, and you can keep the cats for their natural lifetiimes.