In King's Quest II+, Count Caldaur of Kolyma was bitten by a cursed bat and perished, only to return as a vampire after many years' recovery. The drastic change had caused him to abandon his duties as ruler of Kolyma, and focus solely on the protection of his surviving family. His wife, Lavidia, and their granddaughter Anastasia were still in grave danger from the Brotherhood of the Pack, and had to live in hiding down near Kolyma's shore.
After Graham alerted Caldaur to Lavidia's deteriorating health, the Count turned his wife and granddaughter into vampires like himself, so that they could defend themselves against the danger the Brotherhood presented and spend eternity with him. The process aged Anastasia from a small child to young adulthood.