Final answer:
If both parents are homozygous recessive for the Rh-factor allele, the mother will not react to her second baby's blood.
Step-by-step explanation:
If both parents are homozygous recessive for the Rh-factor allele, the mother will not react to her second baby's blood. This is because both parents have the recessive Rh-negative allele. In order for the mother to react to the baby's blood, at least one parent has to be a carrier of the Rh-positive allele.