Given the following context:  On her 18th birthday, India Stoker (Mia Wasikowska)—a girl with a strong acuteness of the senses—has her life turned upside down after her loving father Richard dies in a horrific car accident. She is left with her unstable mother Evelyn. At Richard's funeral, Evelyn and India are introduced to Richard's charming and charismatic brother Charlie, who has spent his life traveling the world. India, who didn't know Charlie existed, is perturbed by his presence. He announces that he is staying indefinitely to help support India and Evelyn, much to Evelyn's delight and India's chagrin. Shortly after, India witnesses Charlie argue with Mrs. McGarrick, the head caretaker of the house. Mrs. McGarrick complains to Charlie that she has been his "eyes and ears" since he was a boy. Mrs. McGarrick then disappears. Charlie and Evelyn grow intimate while India continues to rebuff his attempts to befriend her. Later, her great aunt Gwendolyn visits the family, much to Evelyn and Charlie's dismay. At dinner, Gwendolyn shows surprise at Charlie's claims of traveling the world and tells Evelyn that she needs to talk to her about Charlie. Gwendolyn ends up changing hotels due to an unexplained fear and suspicion of Charlie. However, she loses her cell phone and tries to call the Stokers' home from her hotel payphone. Charlie corners her in the phone booth and strangles her to death with his belt. Meanwhile, India discovers Mrs. McGarrick's body in the freezer and realizes Charlie is a murderer.  answer the following question:  What relation is the woman who is suspicious of Charlie to India?
great aunt