Time passed, and Mara and Amy became the best of friends, bonded through Amy's raising of the baby' gryphon. Of course, the appearance of such a creature brought a boon to her family's failing farm. People came from far and wide to see the fantastic creature, and she became famous along with her owners.
Amy's mother had been frightened of the creature at first, but in time she saw the love the two "children" had for one another, becoming more like sisters and best friends keeping secrets. Even Amy's brother John felt the same, enjoying mischeif with his new "feathery sister". Time passed and years came and went, and Amy and Mara grew into strong adolescents who desired to spread their wings.
With the money from their fame, Amy's mother was able to provide such a chance and on Amy and Mara's 18th birthdays, she allowed them to go off on their own to seek Mara's own kind. Amy brought with her the strange vials, though she never used them herself, even when she was often tempted to.
As to Mary, her disappearance was something of a mystery in town, but in time she was remembered for her kindness and warmth and Mara and Amy attended a dedication of a park in her name before they departed.