It's a fetish. Nothing more. Plenty of people bite in sex, some draw mild blood. Others suck hickies until mild blood. There's pain and scat shit disgustingly heavy.

Airing it as a ritual, makes her weird, crazy Jesus, or vampire, or bound eternally, but nothing nobody else hasn't experienced in some form. Like a blood brothers handshake, communion, vamprism. A kink. It gets people talking, giving her publicity. But I doubt it's much else.