Priscilla works for the Librarian to capture Fables. She's the younger twin sister of Robin Page.
Priscilla's family life is very complicated. She and Robin are the twin daughters of the Bookburner and Prose Page. Making her, Kevin Thorn's granddaughter and Gary's great granddaughter. But for some reason, the Bookburner said he never had children with Prose, meaning she either lied or hid her pregnancy from the Bookburner. Whether to protect her children or to hurt his brother, Mr. Revise raised the twin girls alongside their younger half-sister Hillary like his own. Priscilla wasn't the favored child and tended to get blamed a lot for Robin's errors. Throughout most of her childhood and young life, she had a very nerdy appearance. No matter how hard she tried being herself, it never worked out for her. Even the men she tried to date either had no interest in her or they were interested in Robin. So Priscilla did what's always done for her type, she became someone else. With Robin's help she gave herself a total make over and it worked like a charm. Priscilla went through a lot means to keep people at the Library to like her.
Her many adventures include chasing after Jack Horner since he has escaped the Golden Boughs Retirement Community. Though he's always gotten ahead of her and the others when they think they've caught him. However, through this chase he did lead her to the capture of Lady Luck in Las Vegas. And almost came very close to catching him at the Grand Canyon, however it resulted in her getting a broken arm and another librarian almost killed. While they waited a night (mostly to end a feud over who was the copy with Wicked John), Jack claims to Raven that Priscilla Page had a one night stand with him, much to her denial and begs to be put out of her misery than hear him brag.
After reaching a gas station though, he, Gary, and Raven quickly ditch her. It would be later revealed to be true, but not for the reasons he thinks. According to her "aunt" Eliza Wall, when she found someone didn't love her. Priscilla found strategies to remedy that those problems. Eventually, Kevin Thorn would convince Priscilla to help get him out of the Golden Boughs, but it would later be revealed to help his own personal means. As he later had her chased out of his apartment. Eventually after knowing this and finally stopping the Bookburner, Priscilla would get a big shock of her life.
She and her sisters would discover that Prose Page had been involved with Prince Charming and that Jack was their son; thus making him their half-brother. All three horrified to realize that they'd committed incest, Priscilla was enraged and embarrassed. She'd also lend a hand in the Great Fables Crossover by coming to Bigby, Snow, Mr. Revise, and Gary's aid in trying to stop Kevin Thorn from distorting reality. They sent their beloved grandfather to his new universe to start from scratch and choose to stay behind. There, they'd also meet their new nephew Jack Frost II. Whether to keep him from Jack's influence or they just don't want him to end up like Jack, Hillary and Priscilla appear to have motherly attitudes toward him.
Robin seemed to be following along out of reluctance. After becoming mortals, the sisters lived as normal "mundies" for years. Priscilla would become an aunt again when Robin had a baby. A son, named Sammy Jr, as a result of a one-night stand with the Old Sam. The sisters eventually got tired of life as mere mortals doomed to grow old and die, and started searching for Revise's books of original, unrevised Fable stories, knowing that the original books would make them immortal once more.
The search brought the sisters to a dragon, who was in fact a transformed Jack Horner; Jack had stolen the books when the Golden Boughs were destroyed. The sisters arrived at the same times as several former Golden Boughs prisoners, who were on a quest of their own, searching for Fabletown. The sisters went after the books while shooting at the dragon, which made the dragon burn the books - he was tired of them anyway - in anger. During this battle the sisters seemed oblivious that their now grown nephew had come to fight his own father.
The sisters, upset at the loss of the books, started shooting everyone around them. Believing that since they were doomed to die without the books, everyone else could just as well die with them. This made some of the Fables retaliate and all three of the sisters were killed; Humpty Dumpty fired his cannon at Priscilla. While her sisters were killed by the Tin Man killed Hillary and the Cowardly Lion now then ate Robin.