Penelope Johnson, often just called Penny, was a powerful Witch that descended from the The Warren Line and the only daughter of Priscilla Baxter and her husband Gordon Johnson as well as the younger sister to Gordon Johnson the Second. Penelope was married four different times throughout her long life, though it was only with her first husband that she gave birth to her daughter Patricia Halliwell. Through her daughter, Penelope was the Grandmother to the three Charmed Ones as well as the Great-Grandmother of the Ten Blessed Ones.
A powerful Witch in her own right, Penelope had inherited the Warren Gift of Telekinesis. She was also a rather talented Potions mistress and was responsible for creating many of the Potions within her families Book of Shadows. Her falling out with her elder brother, as well as her pain filled love-life, caused Penny to develop a cold bitterness toward men that bordered on loathing.
Penelope met her untimely demise in 1998 when she succumbed to a heart attack, shortly after she bound the Magic of her three Granddaughters. However, Penelope would appear before her granddaughters and great-grandchildren as a Family Spirit that would help guide them and give out advice whenever they seek'd it.
Her great-Granddaughter, Penelope Anne Halliwell, was named in honor of her.