Cause For Positive Benzodiazipines And Amphetimines In Drug Screen?

My daughter went for a job interview and the usual drug screen. No problem, she is drug free. She called my crying, she was so upset. She had tested positive for benzodiazipines and amphetimines. She has been taking OTC medications of benedryl for itchy watery eyes, and dayquil and cough medicine for a really stuffy cold. Could any of these medications have caused a false positive