Bek. Obviously I don't have a 3-y-o so can't give you personal experience, however from books I have read, many youngsters are very big on controlling what they can. Is it possible to reason with her? Like when you are in a hurry and need to dress her quickly?
Perhaps you could have a chat to your family Dr or a MCHN that you trust?
All the best - it must be very trying on your patience!