Jennie Clavell is the mother of Buster Clavell and the grandmother of Xander Clavell. She died as an adult, and her grave can be seen in the Pleasant Rest Graveyard. Like Ransom, she died of drowning. She has long blonde hair and blue eyes, with light skin.
Since Buster is an very old elder at the start of the game, it's known that Jennie and Ransom died a very long time ago, and even if they didn't die of drowning they would've died of natural causes by now anyways and would instead be elder ghosts in the graveyard.