BROOKLYN - FedEx drivers are going the extra mile today to deliver all the last-minute Mother's Day flowers and gifts to women across the borough. "It's good to see the mothers smile today, make them happy," says FedEx deliveryman Hahkeem Pettis.FedEx says its data shows that almost half of Americans think Mother's Day is after May 8, and another 10 percent don't even know when the holiday takes place. FedEx expects to make thousands of delivers today on top of its average daily volume of about 8.5 million shipments.