Her full name is Jacqueline Jane McCartney, but goes by Jackie. She is slightly taller than girls her age, standing at 5'0”. She has slightly wavy reddish brown hair that is about to her waist, and the front is neatly cut in a fringe. She always wears it down with a headband. She has fair skin which has many freckles, and light hazel eyes that look almost green in some light.

She is often described as mature for her age. She is well-mannered, quiet and reserved. She notices everything, and watches the world. She loves reading in a quiet nook in her house, and listening to her old records.

The McCartney family is a pureblood family that settled into Liverpool a long time ago. Her father, John McCartney is stern and disciplined. Her mother, Charlotte McCartney, is also disciplined, and doesn't coddle her. She has an older brother, Charles, and a younger brother, Phillip. She has the closest bond with her grandmother, Norma McCartney. She is homeschooled and her grandmother teaches her basic subjects, and family traditions. Her favorite subject is reading because she loves reading the classics. She had one muggle friend, Adelaide whom she met at the library a long time ago. They were very close, until one summer Adelaide moved away. Jackie didn't tell anyone this, but she cried herself to sleep for a week.

Her first instance of magic was when she was eight. Her grandmother left clothes on the clothesline to dry, but she noticed rain was coming. She told her grandmother, but her grandmother only told her not to worry. Jackie kept on worrying. When she saw many little drops, she closed her eyes and admitted defeat. The rain would surely ruin the clothes. To her amazement the rain suddenly stopped, and skipped over her yard to the street nearby like nothing ever happened. She was initially confused, but her grandmother explained that she just had her first instance of magic.