Blood — Kate Pavelle

As Lucien, the millenial vampire in search of "ethical blood" regains his memories, his renewed contact with his cousin Lauren reveals that she's allergic to garlic.
Intersting... it might be a false alarm, but it might also mean Lauren will soon need a guide to the world of the Undead.
This stand-alone short story is one of several in the Lucien Honore Martel world, where Millenial vampires seek consensual blood donors the way they used to hunt down sources of organic baby kale while still alive.