Loralai 'Rory' Gilmore and Victoria 'Tori' Gilmore are the twin daughters of Loralai Gilmore. The two sisters while similar in their love of books and academics, differ in many other ways. Tori is just as much the Stars Hollow sweetheart as her sister, but she is much more confident and outgoing than her socially awkward twin, and while her Rory has dreamed of going to Harvard for Journalism her whole life, Tori has her heart set on Yale.
The two sisters are the best of friends along with their mother, but when the girls get into Chilton and Tori meets a boy, their life begins to change.
Lorelai had twins Rory and Romeo. Obviously one of them was her favourite, the other being their father's favourite. Resulting in both twin's being jealousy of each other. Romeo didn't hate his mother but he also didn't like her. It was more the fact he was like her in so many ways. That was the problem she couldn't love something so like herself.