Isabelle was born on April 1, 1952. She died at the age of 50, on April 12, 2002 due to an unknown reason. She was mentioned by her sister, Victoria, during the murder investigation of her son, Daniel. Victoria told the team that Isabelle had died 10 years ago when Daniel was just 15 years old. After his mother's death, Daniel lived with his aunt Victoria.
In the Additional Investigation of the case, Jones and the player would go check up on Victoria. She told the team that ever since Daniel died, she felt weaker than usual. Her health kept troubling her and she felt depressed. She kept thinking about her attitude towards Daniel and how she should have acted nicely instead, and wished to have behaved differently with him. She also said that she has old photos of Daniel with her sister, Isabelle, Daniel's late mother, in a trunk. She then said that looking at those memories may make her feel less lonely, but the trunk in which the photo is kept was in her house's dusty attic protected with a code she forgot a long time ago. The dust at the attic was bad for her lungs and so she asked for the team's help. The team then began by investigating the attic. After searching it thoroughly, they found the heavily loaded trunk locked with a code. After the team cracked the code of the trunk, they found a lot of photos inside it, and then gave the trunk full of photos back to Victoria. The team apologized to Victoria for opening the trunk to see if it was the correct one, but she comforted them, telling them that it was okay since she did not remember the code anyway. The team then suggested Victoria to not stay indoors all the time since it might get her health better. They also suggested her to grow flowers in her garden since she likes gardening. She agreed and thanked the team for their help.