I keep thinking of implications with Alecto coating her sword with Harrow’s blood, since it’s presumably also had Anastasia’s blood on it (’placed the child’s hand upon the blade, so that it received also the red blood of the child’)

and before that Alecto was able to call off skeletons with raising her sword (’many skeletons emerged from the bones of the bier, and from the walls of the tomb, but when the sword was raised, they fled’), so does Alecto still has some power over necromancy or it’s side effects of Anastasia’s blood