Very quiet

Hetty has been so quiet all day, no running around the garden and only playing when tempted and then not for long.
This evening she just wants to sit on a blanket on my lap.
Not like her and we have checked her over and there doesn’t seem to be anything wrong and she is eating. I wondered if it is something to do with her vaccine yesterday. If she is no better tomorrow I will call the vet.
Spoke to brother, who is still getting lots of pain a week after his operation, planning to visit him tomorrow.