Elizabeth Bathory

The vampire Elizabeth Bathory is a fictional continuation of the real life Countess Elsabet Bathory.

Everything you've heard of the Blood Countess from history is true, except it was lambs blood. She did murder 666 teenage girls and young women in her quest to attain the same immortality as her bloodfather. Eventually, when that didn't work, they made her a vampire the normal way of exchanging blood and killing her.

Throughout the books Elizabeth Bathory is referred to as Elsa. Elsa is described as shorter than Shauna with pale skin and long raven black hair down to her waist. She has hazy-blue eyes according to James in Blood Atonement. The cover also depicts her eyes as blue. The actual historical figure probably had brown eyes. In Blood Armistice, she mentions she was created as a vampire with Brown hair and Brown eyes and her hair darkened over the course of the following decades while her eyes became blue.

She first appears as a goth patron at the club, Grue's Home, where she helps Shauna select wine. The next time we see her is at Amber's house, where she adopts Shauna in James' absence. From that point on in The Blooddaughter Trilogy, Elsa and Shauna are nearly inseparable.

Blood Atonement goes back into her past and describes the true history (within the world of The Blooddaughter Trilogy) she had been coerced by James to remember differently.

Pets
In The Blooddaughter Trilogy, Elsa has the identical twins Jackie and Jonnie as pets. She is unique in having two pets at the same time. In Blood Reprisal, she takes on Moana as a pet.

In Blood Atonement, Elsa starts with Pepa as a pet. Elena is mentioned as a prior pet. Later Elsa has Jonathan Gainor as a pet but ends the main body of the book with Karina and Katina as pets. The epilogue of that book jumps to the time where Moana is her pet.

In Blood Armistice, Elena Nadasdy is mentioned as Elsa's pet for most of her first century as a vampire. Elena's death leads to the events of Elena the Hunted.