Being the only daughter of the illustrious Hamburgang family, young Rosalie Hamburgang was doted upon by her parents, the servants of the house and the family's personal alchemist Jude.
Her Part on the Story
When the girl died at an early age from an unknown cause, Jude vowed to bring her back to life with Human Transmutation. The experiment ultimately proved a failure, robbing Jude of his eyes. In order to spare him the additional grief of learning that he had failed the transmutation, Rosalie's father instead told him that it had been a success, and he ordered that the truth be kept hidden from Jude. They then preserved the body in the West Wing of the mansion, where an unknown and silent soul seems to reside in the grotesque, mummy-like corpse.
The Girl called Amy
Requiring a stand-in for Rosalie so that Jude would not learn the truth, the Hamburgangs visited a local orphanage and adopted a young girl named Amy, who happened to resemble their late daughter almost identically. The new "Rosalie", a rambunctious and curious young girl, reveals the truth to Edward and Alphonse Elric when they come to the Hamburgang estate to investigate Jude's "success" and shows them the questionably living body that resulted from the Human Transmutation.
When asked by the Elrics why she continues the charade instead of returning to the orphanage, Amy replies that she is comfortable in the Hamburgang estate; her life has improved since she began calling herself Rosalie and the new family she had gained treats her very kindly.
While unconfirmed, it is possible that Rosalia Lombardo may have been the inspiration for Rosalie and the Bonus Chapter: The Blind Alchemist. Being one of the most well-preserved mummies to date, the story bears many similarities to the one featured in the Fullmetal Alchemist series. For example, their names are similar, brownish hair, each was born as the only child of a wealthy family, and both died at a young age, being subsequently preserved as mummies by their fathers.