She eventually chooses Stefan in the season finale but before she can tell him, Elena drowns while having vampire blood in her system; she then awakens as a vampire in transition.
In season four, Elena must decide whether to die or to feed on human blood so she can fully transition into a vampire.
It is later revealed that he is a 162-year-old vampire.
Stefan's brother, Damon, also begins falling for Elena.
In season two, she learns that she is a Petrova doppelgänger, exactly resembling Katherine Pierce, which means that she can be sacrificed to release Klaus' werewolf side.
She has an adoptive aunt named Jenna Sommers who serves as her and Jeremy's legal guardian in the first two seasons of the series.
After Stefan and Elena sleep together, she finds a picture of a woman named Katherine Pierce who looks exactly like her.
Stefan reveals that this woman caused the brothers to feud 145 years ago, and turned them into vampires.
In season three, Elena does everything in her power to make Stefan regain his humanity, which he switched off to satisfy, and tolerate, Klaus.
She grows closer to Damon while working together to save Stefan and try to defeat Klaus, eventually sharing a kiss.Damon makes Elena turn off her humanity to avoid her grief when Jeremy is killed searching for a cure for vampirism. When she turns on her emotions again, her sire bond to Damon has been broken, though she remains in love with him.