Your mother is suffering from carcinoma of gall bladder
and has been operated twice. if she has not been treated with raditherapy to tumor bed followed by adj. chemotherapy
the cancer is liable to reccur. Suffering from 1 day fever
can be because of infection. for which conventional treatment / symptomatic treatment is needed. Have her blood culture
and sensitivety done and treat her with appropriate antibiotics. Else visit your physician to get her investigated for recurrence.