They are werewolves from the Quilete Tribe. They don't appear until Eclipse.
Seth Clearwater's sister in the Twilight series is Leah Clearwater. She is also a member of the Quileute tribe and a shape-shifter, like Seth and the other members of their pack.
Leah Clearwater
In the "Twilight" series, Seth Clearwater's real name remains Seth Clearwater. He is a member of the Quileute tribe and belongs to the wolf pack led by Sam Uley.
Rosalie she did have an other sister when she was human.her name started with a C.....
The sister's name was Cynthia..
Rachel & Rebecca
Seth/Set is the Latin form of the ancient Egyptian god's name.
Alice's sister's full name while she was human in Twilight was Cynthia Brandon.
Rachel and in case you were wondering, Paul imprints her.
Alice doesn't remember, so you'll have to read the book.
Twilight Sparkle's middle name is actually "Twilight". Her full name is Twilight Sparkle.
Cynthia Brandon
They are brother and sister.
No. Thank God.