Vablatsky’s death date was given on a Famous Wizard Card in the video game adaptation of Harry Potter and the Philosopher's Stone, which takes place in 1991-1992. Vablatsky’s death date is given as 6 years later. This could be a reference to the Seer's skills, given that she could have predicted her own death.
She was likely named after Madame Helena Blavatsky, a 19th-century psychic and founder of the Theosophy movement and early proponent of New Age philosophy, who was declared a fraud in 1885 by the Society of Psychical Research. She was known for fusing ideas of modern science with esoteric tenets of Eastern spirituality.