I have no experience here, but wanted to chime in and say that I could see how being with the other dogs, which she isn't used to, might be upsetting to 'your highness'. Not sure though whether this would actually make her vomit. Others, with experience here, should be able to answer that one. I'm glad to have read that things are improving... and I hope they continue to!!
They are such a worry sometimes.
She's a lucky one to have you!!