They explained it in the manga she's not related to the family with paladin powers her mother who married in cheated on the father.
It is confirmed that the mother cheated? :o
I thought that there will be some kind of reveal that this is not the case. Is anywhere explained who the actual father is?
Actully no, from the last light novels look like the problem was the mother bloodline.
Queen Lacey La More, a former Duchess of La More become a Lycanthrop almost immortal, in Volume 6 try kidnaps the Duke Daughters but leave behind Melida & Mule because one "even if from the noblest bloodline she was tainted from a vampire" & the other because was not a real member of the La More family.
Is there any explanation for it in the novel? Pretty please tell me if you know.