Patty Halliwell died and when she was to go on to the afterlife, she was approached by an Angel of Destiny and the Elders to either continue on to the afterlife, or to be reborn and continue the fight against evil. She chose to be reborn and was reborn as Buffy Summers, the Slayer.
Paige Matthews is assigned to be Buffy and Dawn Summers Whitelighter when they come into their powers.
Instead of Spike learning that Buffy had been in Heaven, it is Dawn who learns. Dawn in an attempt to help Buffy, get over what Willow had done to Buffy by yanking her sister out of Heaven, calls her birth mother, Prue Halliwell
What If Paige had not been adopted by the Matthews family. What if she had been adopted by the Summers family. And what if she had acquired her powers before season 4 of Charmed. This is the story of the Summers family own Power of Three. Paige (16 1/2) Wiccan Witch, Buffy (16) the Slayer/Gypsy, and Dawn (14) a Wand Witch/Gypsy.