Hi Anniemm
I'm so glad you are working with a vet and an experienced mentor, what an exciting time coming up! With goats or cows because they have been bred for high milk production they are more likely to experience what is commonly called milk fever when they suddenly have a great need for higher calcium and the calcium levels in their blood drop drastically due to their production. Although this is pretty typical in a dairy specific animal and less common in other animals, it is definitely still an issue that can occur in dog breeds. Did your vet feel that it would be unnaceptable or harmful for some reason? Because if he wasn't against it but just didn't feel it was necessary than I would want to err on the side of caution and go with the calcium myself. If he is concerned however that h high levels of calcium in addition to her current diet and supplements would put her at risk for calcium deposits in her kidneys or something like that, then I would heed the Dr's orders for sure. My background is in farm animals though so perhaps an educated breeder will chime in with their experience as well
best of luck with the upcoming babies!