By the time I was on Eurostar on Friday evening my throat was feeling pretty raw as well, and I got home to find Anne in pretty much the same state. And yesterday B (who returned home a week ago) started the morning by gently puking upstairs. By the late afternoon U was in misery, and her temperature had soared to 40.8 (105.8 in your antiquated counting) so we called the doctor, who prescribed antibiotics and suggested we take her to hospital for a lung X-ray if she hadn't improved by today. (F has recovered fully.)
However; things have improved. I cooked a large chicken curry last night, and B, despite her earlier stomach complaints, dug into it gleefully, with no apparent ill effects (indeed, if anything, the reverse). That cheered me up as well; communicating with B is not easy and I feel that cooking her food she enjoys is one of the special things I can do for her. And by the end of the evening, U had also perked up, helping us watch classic music videos off YouTube; this one sent her into peals of laughter. Which is reassuring, at least on most levels.
My throat is still sore but improving. Why is it these bugs usually hit you at the weekend?