This is really tough tbh.
how many times have we felt like crap.of a morning but after some rest and some food we feel ok?
There doesn't have to be any lying or faking involved. She could genuinely feel better having actually been rough in the morning.
managing six hours at school forced to sit in uncomfortable chairs and not allowed to take any medication is different to managing at an event for a couple of hours having managed to control the pain successfully all day.
quite often I had stomach ache at school because of sitting badly and having nowhere private to ease the wind
.
I'd have been fine after being able to rest and have a bath and not hold things in all day.
I'd also be thinking about periods maybe? and again I dint think. you can punish someone for period pain that's controlled by the evening.
You know your dd best, if she's got form.for faking or you think she's genuinely still ill and hiding a bug then keep her home.
but I'd be careful also about sending the message that you automatically think. She's lying.
If this is period pain kind of thing then it's going to he something she can't help and missing out on things isn't going to be fair.