Grace is known for being exceptionally kind hearted, stubborn, strong-willed, compassionate and caring towards others. She is an extremely loyal, brave and selfless person. After growing up as an only child for nearly fourteen years, Grace can be considered to be very independent. She struggled to regain some of that independence when she met Harry and discovered that he was her twin, which was thought to be the reason why she isolated him when they first met.
Grace has a tendency to underestimate those around her, mainly because of her concerns for their safety. She has a sharp tongue when in temper, and has no problem standing up others, or for what she thinks is right. Her personality is described to be very warm, giving Grace a very inviting and kind aura about her. Grace cares very deeply for those around her, especially her loved ones, and is willing to put the safety of those she cares about above anything else, including her own safety.
She is said to be quite intelligent and talented, a trait she inherited from Lily. Much to her annoyance, many people who knew Lily would always comment at how much she and Grace were alike, personality wise and looks wise. Despite having never actually meeting her birth mother, Grace has been said to share many traits that Lily had, such as having a knack for potions, being kind hearted, quick-witted and compassionate, and even seeing the good in others. She also inherited her father's talent for trouble, as Grace was known to be quite mischievous as a young child.
After the sudden murder of both her adoptive parents, Grace's once bright and optimistic personality dulled a bit, and over time, she developed a barrier so to speak, hiding her true emotions at bay. She carries a considerable amount of guilt for her adoptive parent's death, because she feels as though if she hadn't gone out that night, and if she had been home when the death eaters showed up, then her adoptive parents might have been spared their torture, and may have not been killed. Nevertheless, once Grace came to terms with her new life, her personality slowly improved and she became more open towards others.
While Grace is able to maintain a normal attitude under stressful situations, she has been shown to be emotionally fragile, and sometimes cannot bare the emotional burden of some events.
Grace is noted to be very beautiful, and the near-spitting image of her mother, with the exception of the jet-black hair that she inherited from her father. Her facial features as said to resemble Lily greatly, including her distinctive bright green, almond shaped eyes. Many people who knew Lily would always comment to see her through Grace's familiar green eyes.
She has a very pale complexion (which makes her hair appear darker than it naturally is), with long wavy jet-black hair, a window's peak, unique green eyes, a heart shaped face,a thin nose and prominent cheekbones. Her eyebrows are dark, and are more straighter than they are arched. She is tall and slender, standing at 5'6, a trait that both she and Harry inherited from James.