Maybe she thinks it's play time? Are you "yelping" or saying "ooouch!" when she bites? Try giving her a stuffed Kong toy or bully stick or something to keep her busy while you are handling her paws. Or maybe get her nice and tired first. Go for a long walk or let her play and romp with other dogs for an hour, and right when you get home and she flops down to relax then get the clippers and try then.