The abused twin- HP

Harry Potter had a sister that only a few wizards knew about. Dumbledore thought it would keep her safe.
They both lived with the Duresly's but Harry was treated like a prince. He and Dudley were like brothers and they both got whatever they wanted, where as Harry's slightly older twin sister was treat like a house elf.
A prophecy wad made but it said, " The ones with the power to vanquish the Dark Lord approaches... born to those who have thrice defied him, born as the seventh month dies... and the Dark Lord will mark them as his equals, but they will have power the Dark Lord knows not... and either must die at the hand of the other for neither can live while the other survives... the ones with the power to vanquish the Dark Lord will be born as the seventh month dies.... One of prueity the other of hate."
Who will be the good one? Will it be the one treated like a prince or the one treated like a house elf?