Penny Halliwell

In the Comics
Year One: Grams' death is mentioned.

In Unnatural Resources, she showed up to meet her youngest great-granddaughter and namesake, Prudence Johnna Halliwell. She then proceeded to give her the nickname of PJ, which distressed Phoebe a little, because she figured it would stick.

When Kyle Brody brought Paige's spirit to her and Patty for help in Last Witch Effort, she helped gather the Warren witches together to return Paige where she belonged and help defeat Neena.

In The Charmed Offensive, she was one of those who helped casted the binding spell on Neena.

Volume 1

 * "What else would you call Prudence Johnna Halliwell?" - Unnatural Resources

Volume 2

 * "That was a nice break from the norm. Glad to see I still have some fight in me." - The Charmed Offensive

Volume 3
She hasn't said anything as her only appearance in this volume was a flashback.