Thanks to @Pumpkintopf and @Baaaahhhhh for your comments on below standard grade offers. I think DD is just particularly stressy at the moment. Although she hasn't had tests, she's found this week particularly difficult, with two courseworks due in, the three Oxford essays to do/finish, and news of a surprise mock in December.
I hope your test-sitting DC feel a weight has been lifted as they get through them. I know that some have mentioned that their DC don't think they have done well, but I guess this will feel different to exams they've experienced before?