MY best friend is beside himself because he want to know if his ex-girlfriend is has his baby . And she refuses to have a paternity test . Can she do that?

The answer is simple. File for custody in a local Family Court. They will order a test be done.

In your subject you indicated the problem is yours, then you claim its your friend's. Please don't play such games. It doesn't matter.

MY best friend is beside him self because he want to know if his ex-girlfriend is has his baby . And she refuses to have a paternity test . can she do that?

Sure she can, until a court orders her to allow the child to be tested.