Frank's Links
"Is this guy my boyfriend? I think so he treats me like his girl... it's nice."
The few that Cardner can trust or even tolerate, he really loves Frank in his own odd way, splitting the kill he makes with her to help stave off her need for flesh time-to-time. Is it love? Maybe.
Apparently Frank is their distant sister from another marriage on their mother's side, but barely known of her until after her death. Sadly, they know nothing about how or when she actually passed away.
Frank's sibling but not from the same father, they are quite suspect at first of the idea of having a sister until there was too much proof that they are indeed related and now feel a moral obligation to watch over her from a distance, keeping an eye on Cardner.