Under the laws of all states in this country, one's employer can legally ask for medical back up such as a doctor's note verifying why the employee was unable to make it to work on a particular day.You write that your daughter was ill and you took her to the emergency room resulting in a call to your manager at work stating that you would miss work that day due to illness in the family. Your daughter's physician's note stating that your child was ill on this particular day would verify your excuse for not attending work on the day in question.