In this case it is not clear if the surgery is going to be for the same condition or not. If the condition is same, ask her to submit the new certificate within seven days. If this is a different condition than the condition that she was out for 8 weeks, then she has fourteen days or two weeks for get that certificate because it is a brand new condition and for every new medical condition under FMLA and CFRA you get a week. Right now this person is not compliant because she was supposed to back on May 1st. She gets 14 days plus 3 days and she will be terminated. Employees don’t have to inform employers about the medical condition unless they are dying or they are completely incapacitated like they can’t even speak or read, or get the mail.
You can make a call to her and say that are you out of the work due to the original medical condition or a new one, I need a message within 3 days.