For the Blood Is the Life is a 1905 (or 1911, according to some sites) short story by Francis Marion Crawford. It can be read online.
The Literary Gothic says,
This is a popular and much-anthologized tale of Crawford's, probably owing to the fact it's a "vampire" tale, but that's a shame; it's hardly Crawford's best workAmericanaEJournal says,
vampire fiction at the turn of the century was obviously conservative; it represented a moral lesson and showed a yearning towards the stability of gender roles with the figure of the vampire as a threat to the existing order. In these narratives the conformist, subordinate women were put on pedestal whilst non-conformist women were destroyed.