Leah Clearwater born sometime in 1986, is a Quileute native american and a member of the Quileute wolf pack. She is the daughter of Sue and Harry Clearwater and the older sister of her brother Seth.
Leah met and dated Sam Uley, a man she met in high-school. They were said to be deeply in love with each other throughout the course of their relationship.
When Leah brought her cousin, Emily Young to meet Sam, Sam ended up leaving Leah for Emily. The cause is later revealed to be that Sam imprinted on on Emily. Leaving him no choice but to leave Leah. Though, Sam never stopped loving Leah. This left Leah with a broken heart and she became a bitter and angry person as a result of this.
Not much is said about Leah in New Moon except for when Bella Swan and Charlie went to a house party thrown by the Clearwater's. It is said that Leah spent the whole night on the phone. Later on in the year, her father, Harry, suddenly dies of a heart attack. The reason is believed to be because Harry found out that Leah was turning into a werewolf. The shock of his death is believed to be the reason why Leah first phased.
In Eclipse, Leah and the rest of the pack continue their fight to try to kill Victoria. Leah's bitterness is even worse because of her forced proximity to Sam Uley who is the pack's alpha. She resents Bella for the pain she is causing Jacob by her choice to stay with Edward. The pack can see in Jacob's mind and can see what Bella can't.
Edward at one time tells Bella that while most members of the pack tried to make things easy and not cause any more problems than there already was, Leah brought up mental images of the mental pain she went through when Sam left her. She also is said to have brought up issues regarding Embry's parentage. Because, Embry's home-life was less than stable. No father is ever mentioned.... rumors around the tribe were that either, Sam Uley's father was the father of Embry. Making Sam and Embry half-siblings, or Billy Black was Embry's father. The pack chooses to believe Sam is the one, because Sam's father already had a bad reputation.
She is seen briefly in the bonfire in La Push when Billy Black was telling the group Quileute legends. According to Bella, at one point, Leah appeared to have a single tear slide down her cheek. Leah fought with her pack when a newborn army of vampires descended upon Forks. The army, headed by Victoria, were all defeated by the wolf pack. After the battle, one lone vampire remained, and Leah, being the sole female member of the pack, tried to prove she was as tough as the rest of them, attacked the vampire. Jacob, trying to save her, shoved Leah aside. Jacob was ultimately hurt in the battle.
After the battle, Leah is seen trying to persuade Jacob to get over Bella, while at the same time, telling Jacob of a dream she had had of her and Bella kissing. Jacob later makes her leave after a nasty remark about her relationship with Sam.
In Breaking Dawn, Leah is said to openly disapprove of the friendship her brother, Seth, had made with Edward Cullen. Bella is said to even avoid talking to Leah just for this reason. Leah does attend Edward and Bella's wedding at the Cullen house but does not stay for the reception.
Not much else is mentioned about Leah until Book 2 which is told from the point of view of Jacob.