My DD is 6 and is quite fastidious about hygiene, and is becoming quite fearful of anyone vomiting. Within the last year she has had maybe one bout with a stomach bug and she hated it (who wouldn't) but also coped quite well with it and bounced back fine.
Last week her brother, age 3, got a bug and was sick just once at bed time. She didn't see it happen but she heard it and ran into our bed to sleep there - they share a room. I was ok with that as it meant I could sleep in her bed and keep an eye on him over night.
He was pretty much better the next day, but DD has since refused to even be in the same room as him. Today was the 3rd day of this. She has refused to eat at the table, to be in the car, to sleep in the same room or even to play in the same room. If he is elsewhere she is fine - her normal happy self. If he comes near she starts to cry in an afraid way but won't say what's wrong.
We got to the end of our tethers with this today and ended up physically forcing her into the car but she freaked out completely. We've tried a lot of being kind gentle and encouraging her to talk but it isn't working. Her little brother has been really sad today as he has worked out she's avoiding him and I'm out of my depth don't know how to reassure her and how to limit how it could affect him. Plus it makes every meal time and activity impossible and stressful.