It depends how treatment goes. From what I learned about this protozoa, it can be very difficult to treat, and even when a treatment appears to have done its job, it is possible for the dog to have relapses.
About breeding from her, I am unsure. As Leishmaniasis can be very stressful for the kidneys, and possibly other organs too, pregnancy may put added strain on her.
I would definitely ask your vet's advice about this.
I would talk to your vet about this but here is what I found .....
Transmission
Traditionally canine transmission is directly from Sandfly to Dog. Cases in the United States have proven Leishmania Infantum transmission from dog to dog by direct contamination with blood and secretions as well as transplacentally from an infected ***** to her pups[8].
This mode of transmission seems to be unique to the Leishmania Infantum Mon1 strain found in the United States, a Brazilian study of 63 puppies from 18 L Donovani infected parents found no evidence of congential or transplacental infection