This resource is found in the following locations:
The wife of William Birkin, and mother of Sherry Birkin, she helped her husband develop the G-Virus. She is determined to avenge her husband's death, she has become so paranoid that she believes everyone she meets is an operative from Umbrella coming to steal the G-Virus sample.
You meet Annette several times during the game, in the Sewers and in the Laboratory. She doesn't come across as being very pleasent, but she reveals to Leon the truth behind Ada's reason for being here, and how Raccoon became infected so quickly.