Generally speaking, direct relatives should not give each other blood transfusions unless absolutely necessary.
This is because such transfusions are more likely to cause complications and side effects, and the chances of triggering latent hereditary diseases are also greatly increased.
As a reader with an omniscient view of this world, Arabella knew Zachary Donovan's true identity, but Hugh Donovan did not.
So, at his insistence, the nurse transfused his blood into Zachary Donovan.
What was originally just a head injury with significant blood loss requiring a transfusion ended up causing much more severe complications because of that transfusion. A perfectly healthy child was nearly lost.
Seeing this, Arabella Donovan almost rolled her eyes. She felt sorry for the child for having such unreliable parents.
