It is true you should never breed from dogs in their first heat. However, ideally the minimum age for breeding is 2 years. This is to assure that she is fully developed mentally and physically and any genetic defects she may pass onto her offspring have had time to surface. Breeding under 2 years increases the likelihood of a Caesarean birth which is costly and poses certain risks, and it also increases the chance of the puppies being rejected and mismothering.
