Gertruda has pale skin, very long dark hair, and large blue eyes.
Gertruda is a young woman from the Village of Barovia. She ran away from home and wandered on her own to Castle Ravenloft and asked the lord of the land, Strahd Von Zarovich, if she could stay. He granted her permission and she began living there. It's very likely that Strahd was drinking her blood while she was living there. Anastraya Karelova suspected he would marry her someday.
When Cherish Heiss Wished for Strahd and his consorts to be good, Gertruda was seemingly unaffected, as she was not his consort. However, she did appear aboard the Snail Rail, headed for Mordentshire. Like the party and consorts, she seemed to have amnesia, suggesting that she was affected by the Apparatus, if not the Wish.
Later, in Mordentshire, she was bitten by Strahd, in the form of The Beast, and turned into a Vampire. In the Spring of 1496, she moved to Waterdeep to live with Ludmilla Vilisevic, Anastraya Karelova, Volenta Popofsky, and also her loyal friend and guardian, Lancelot, at the The Blushing Mermaid.