Nope..no additional information...that's ok thanks for asking! I'm going to ask some university lecturers too so if I get the answer I'll let ye all know :)
So there I was thinking, if the mother was Rhesus Negative and she had a Rhesus positive baby, her antibodies would cross the placenta and attack the Rhesus positive baby's red blood cells (assuming second child).
Then I thought, well, what if the mother was Rhesus positive, and the baby was...