Further investigation has revealed that Ms. magenta is in fact not Ms. Rose's mother. Because of a ...

Uh, so i just finished my Genetics course 2 weeks ago so i don't know how accurate i am but here is my shot at your problem.

A. Ms. Feather's phenotype is hemoglobin with carbohydrate A and B attached to it. Her Genotype is AB.
B. I would say no because there is not enough information to exclude the potential father since there is no information on the daughter's genotype or phenotype.
C. I don't think there is a chance that rose can be type O because Ms.Feather's genotype AB which is dominant and type O is recessive so you would need two recessive O allele to be type O, therefore even if the father is type O, the child's blood type will still be AO or BO but technically just A or B because O is recessive.

Hope this helps.

Thank very much for your help. So, for the questionC, none will be Ms.Rose's mother or father. Am I right?