My fearful child

A while ago my ten year old child was sick of a stomach virus and got sick,she vomit a coupe pf times at night she had fever, after a few days she got better,but know she will not step in the bathroom that she vomited in and she will not let it rest we have to go to lunch with her everyday and she is afraid if we don't show up, please help for resources,she is not eating as a normal girl her age would, she is now eleven, took her to a pediatric doctor, the inform me she is okay.