You have to stop,pause a while & think.What is the problem,probably there is something about you which doesn't please other.It may be the way you talk,bossy type,pretending to knows everything,etc..If none of this you possessed,just ignore her.Try to bring out the best in you & prove to your boss that you are right but if there is really something wrong about you, then it's high time for you to change for better.Step on the ground.