Hi coaches I have another question is the Duke man to man a good d to teach? Or do you consider that a zone?

Duke plays primarily M2M using some zone principles. Now for your question, it depends on the age of the kids you are coaching. If they are very young, then keep it basic, ball side.....help side and basically stay between your man and the basket. However if you are coaching JV or Varsity, you can implement any system you desire. coach Mac

It is 3rd and 4th grade girls and you can't double team in the league we are in.

Coach Mac nailed this...

Teach good on the ball defense... and then help side - they are very young, so IF you can get this across, you will have accomplished a lot.