High white blood count is a nonspecific evidence for urinary tract infection
. You need to do urine culture to confirm diagnosis and also give the appropriate antibiotic based on culture. If you every much concerned then its worth admitting her and doing all tests for fever
including urine culture. Injectable antibiotics will help if there is no response to omnicef
even after 48 hours of giving them.
Dr. Balaji Chinnasami MD