I think that the references to Carmilla's "family" is a way giving what is a rather short localised novella an extended context. It means that Carmilla is only one facet of a problem which is part of the wider world of the book. She dies but there are others. They continue.
Personally, i found the actual horror of the tale lay in the psychological terror combined with a diseased acquiescence created in the mind of Laura. There is also the reference to the fact that a mindset which puts total reliance on "natural" explanations can be disastrous. This is even more powerfully seen in another novelette, "Green Tea". That awful, awful Monkey could be a psychological construct or it could be real. Maybe it's both. The altogether too facile "natural" assurances of Dr Hesselius at the end really fail to convey any certainty. And I don't think they are meant to do so.
BTW, one of the interesting features of the Scholarly Edition is the wealth of material about other literary references to the vampire including complete texts, e.g. Stoker's "Dracula's Guest" which are in an extended appendix.
Last edited by fantasyfan; 10-29-2012 at 12:15 PM.